Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| the distribution and effects of dippu-allatostatin-like peptides in the blood-feeding bug, rhodnius prolixus. | using a polyclonal antiserum to dippu-allatostatin 7 (dippu-ast 7; formerly ast 1) of the cockroach diploptera punctata, we have demonstrated the presence of ast-like immunoreactivity (ali) in cells and processes throughout the nervous system, gut, and peripheral tissues of unfed fifth instar and adult rhodnius prolixus. ali in apparent neurosecretory cells of the brain, suboesophageal ganglion, and mesothoracic ganglionic mass, as well as in midgut endocrine cells, suggests that rhodnius allato ... | 2003 | 14706534 |
| lipophorin interaction with the midgut of rhodnius prolixus: characterization and changes in binding capacity. | several classes of lipids are transported in insect hemolymph by lipophorin, a major hemolymphatic lipoprotein. the binding of lipophorin to the midgut of the hematophagous insect rhodnius prolixus was characterized in a midgut membrane preparation, using purified lipophorin radiolabelled in protein moiety ((125)i-hdlp). lipophorin specific binding to membranes achieved equilibrium after 30-40 min, was sensitive to ph, and was maximal at ph 7.0. in the presence of increasing concentrations of me ... | 2003 | 12650691 |
| inhibition of hemostasis by a high affinity biogenic amine-binding protein from the saliva of a blood-feeding insect. | the saliva of the blood-feeding insect rhodnius prolixus contains numerous pharmacologically active substances. included among these are a number of lipocalin proteins that bind various ligands important in hemostasis and inflammation. one such protein is a biogenic amine-binding protein (abp) that binds serotonin, epinephrine, and norepinephrine. based on amino acid alignments, it is most similar to the nitrophorin group of lipocalins found in the same insect species. physiologically, this prot ... | 2003 | 12464610 |
| further morphological studies on the behavior of trypanosoma rangeli in the hemocytes of rhodnius prolixus. | the hemocytes of rhodnius prolixus were analyzed during the course of infection with the protozoan trypanosoma rangeli. the following cell types were identified: prohemocyte, plasmatocyte, adipocyte, granular cell and oenocytoid. the number of these cells changes during the infection course thus indicating a cell response to infection of r. prolixus by t. rangeli. transmission electron microscopy showed that plasmatocytes were able to ingest epimastigote forms of the parasite, which were then fo ... | 2003 | 14665386 |
| the chagas vector, triatoma dimidiata (hemiptera: reduviidae), is panmictic within and among adjacent villages in guatemala. | trypanosoma cruzi, the hemoflagellate parasite and cause of chagas disease in latin america, is carried by triatomine vectors, principally triatoma dimidiata and rhodnius prolixus in central america. to assist control efforts and to understand the epidemiology of the disease in guatemala, the population genetics of t. dimidiata was analyzed among three houses within a village and two adjacent villages in guatemala. eleven randomly amplified polymorphic dna-polymerase chain reaction (rapd-pcr) pr ... | 2003 | 14680107 |
| suppression of the prophenoloxidase system in rhodnius prolixus orally infected with trypanosoma rangeli. | investigations were carried out to compare aspects of the prophenoloxidase (propo)-activating pathway in rhodnius prolixus hemolymph in response to oral infection and inoculation of the insects with two developmental forms of trypanosoma rangeli epimastigotes strain h14. in vivo experiments demonstrated that in control insects fed on uninfected blood, inoculation challenge with short epimastigotes resulted in high phenoloxidase (po) activity. in contrast, previous feeding on blood containing eit ... | 2003 | 16256685 |
| prevention of the transmission of chagas' disease with pyrethroid-impregnated materials. | interrupting the transmission of chagas' disease using insecticide-treated materials could be a cost-effective option, particularly for sylvatic vectors, which enter houses at night. a randomized trial was undertaken that included all houses in two communities in regions endemic for this disease, one in venezuela (50 houses) and one in colombia (47 houses). after a baseline study (including a short questionnaire survey, entomologic assessment, and chagas' disease serology), each household was ra ... | 2003 | 12685636 |
| geographic distribution and morphometric differentiation of triatoma nitida usinger 1939 (hemiptera: reduviidae: triatominae) in guatemala. | triatoma nitida was found in 14 (0.4%) out of 3,726 houses located in six departments across guatemala, which were surveyed from 1994 to 1998 by the man-hour collection method. compared to previous information, the distribution of t. nitida in guatemala has increased from five to nine departments; the species is present in mild climates at altitudes from 960 to 1,500 m. fourteen percent of the intradomestic t. nitida were infected with trypanosoma cruzi. the species was often found in conjunctio ... | 2003 | 12700860 |
| lysophosphatidylcholine acts as an anti-hemostatic molecule in the saliva of the blood-sucking bug rhodnius prolixus. | blood-sucking arthropods possess a variety of anti-hemostatic factors in their salivary glands to maintain blood fluidity during feeding. in this work we demonstrate the anti-hemostatic properties of lysophosphatidylcholine (lysopc) isolated from the salivary glands of rhodnius prolixus. first, we examined salivary glands of fourth and fifth instar nymphs for their phospholipid composition. the lumen displayed an accumulation of its phospholipid content, mainly phosphatidylcholine and lysopc, wi ... | 2003 | 12740385 |
| molecular phylogeography of the amazonian chagas disease vectors rhodnius prolixus and r. robustus. | the phylogeographical structure of the closely related species rhodnius prolixus and r. robustus is presented based on a 663-base pair (bp) fragment of the mitochondrial cytochrome b gene. twenty haplotypes were recovered from 84 samples examined, representing 26 populations from seven latin american countries. the resulting phylogenetic tree is composed of five major reciprocally monophyletic clades, one representing r. prolixus and four representing r. robustus. while r. prolixus is a very hom ... | 2003 | 12753218 |
| impact of residual spraying on rhodnius prolixus and triatoma dimidiata in the department of zacapa in guatemala. | as a vector control program to control chagas disease in guatemala, residual spraying of rhodnius prolixus and triatoma dimidiata was performed, and its impact was measured in the department of zacapa. in order to identify infested villages and determine the degree of infestation, a baseline entomological survey to identify municipalities infested with vectors followed by an additional vector survey in areas known to be infested was conducted. residual spraying using pyrethroid insecticides was ... | 2003 | 12764447 |
| transformation of rhodococcus rhodnii, a symbiont of the chagas disease vector rhodnius prolixus, with integrative elements of the l1 mycobacteriophage. | elimination of vector populations through the use of insecticides is the principal means of controlling chagas disease. because of the limitations of insecticide use, we have been developing a new potential method of control, to be used in conjunction with insecticide programs, a method which utilizes genetically modified symbiotic bacteria. these transformed bacteria can express anti-parasitic agents in the gut of the bug where the trypanosomes also are found. previous studies have shown that i ... | 2003 | 12809804 |
| anti-complement activity in the saliva of phlebotomine sand flies and other haematophagous insects. | the saliva of haematophagous insects has a series of pharmacological activities which may favour blood feeding. in the present study, an inhibitory effect on the complement system was observed in salivary extracts obtained from the phlebotomine sand flies lutzomyia longipalpis and lu. migonei. saliva from lu. longipalpis was capable of inhibiting both the classical and alternative pathways, while that from lu. migonei acted only on the former. other haematophagous insect species were screened fo ... | 2003 | 12885192 |
| epidemiology of chagas disease in guatemala: infection rate of triatoma dimidiata, triatoma nitida and rhodnius prolixus (hemiptera, reduviidae) with trypanosoma cruzi and trypanosoma rangeli (kinetoplastida, trypanosomatidae). | a five-year domiciliary collection in the 22 departments of guatemala showed that out of 4,128 triatomines collected, 1,675 were triatoma dimidiata (latreille, 1811), 2,344 were rhodnius prolixus stal 1859, and only 109 were t. nitida usinger 1939. the chagas disease parasite, trypanosoma cruzi, was found in all three species. their natural infection rates were similar in the first two species (20.6%; 19.1%) and slightly lower in t. nitida(13.8%). however there was no significant difference in t ... | 2003 | 12886407 |
| pyrethroid-impregnated curtains for chagas' disease control in venezuela. | the use of insecticide treated materials for the control of chagas' disease transmission is potentially a cost-effective and sustainable option where vectors are sylvatic. a study was undertaken in two rural chagas' disease endemic communities (96 households) of trujillo state, venezuela. after a baseline study (including a short questionnaire survey, assessment of housing conditions, vector behaviour and preferences in vector protection), 37 households were chosen at random for protection by im ... | 2003 | 12943974 |
| amino acids modulate ion transport and fluid secretion by insect malpighian tubules. | insect haemolymph typically contains very high levels of free amino acids. this study shows that amino acids can modulate the secretion of ions and water by isolated malpighian tubules of rhodnius prolixus and drosophila melanogaster. secretion rates of rhodnius tubules in amino-acid-free saline increase after addition of serotonin to a peak value, then slowly decline to a plateau. addition of glutamine, glutamate or aspartate to such tubules increases secretion rates dramatically relative to th ... | 2003 | 12456699 |
| a multidisciplinary approach to the study of the fluminense vegetation. | the fluminense vegetation, more specifically the flora from the jurubatiba restinga has been investigated by a multidisciplinary team of botanists, chemist, radiobiologist, insect physiologists and geneticist. vouchers of 564 specimens have been collected, identified, organized in an herbarium, and a database is being build up containing, in addition to classical botanical data, chemical data and information on the potential economic use either for landscape gardening, alternative foods or as me ... | 2002 | 11960185 |
| allozyme relationships among ten species of rhodniini, showing paraphyly of rhodnius including psammolestes. | genetic relationships among 10 species of bugs belonging to the tribe rhodniini (hemiptera: reduviidae), including some important vectors of chagas disease, were inferred from allozyme analysis of 12 enzyme loci (out of 21 enzyme systems examined), using agarose gel electrophoresis. these species formed two clusters: one comprising rhodnius brethesi, r. ecuadoriensis, r. pallescens and r. pictipes; the other with psammolestes tertius, rhodnius domesticus and the rhodnius prolixus group comprisin ... | 2002 | 11963985 |
| development of symbionts in triatomine bugs and the effects of infections with trypanosomatids. | in the intestinal tract of fifth instars of the hematophagous reduviid bugs rhodnius prolixus and triatoma infestans blood ingestion induced an initial decrease of the concentration of the respective symbiotic bacteria rhodococcus rhodnii and nocardia sp. and then within 10 days a 15- or 18-fold increase of the total population/bug to about 0.8 x 10(9) colony-forming units in r. prolixus and 1.8 x 10(9) colony-forming units in t. infestans. about 95-99% of the total populations of both symbionts ... | 2002 | 11971650 |
| activity and residual effect of two formulations of lambdacyhalothrin sprayed on palm leaves to rhodnius prolixus. | the insecticidal activity and residual effect of two formulations of lambdacyhalothrin were evaluated with rhodnius prolixus; laboratory and field tests were conducted in the state of chiapas, mexico. the results indicate that the lethal concentrations of the active ingredient of sc (lc50 = 2.37 and lc90 = 8.5 mg, a.i./m2) were 4-8 times than those with the insecticide wp applied on r. prolixus bugs in palm leaves, a common building material for thatched roofs. other investigators in south ameri ... | 2002 | 12048565 |
| nitric oxide limits parasite development in vectors and in invertebrate intermediate hosts. | nitric oxide (no) possesses antiparasitic effects on both protozoa and metazoa in vertebrate definitive and intermediate hosts. inducible no limits parasite development also in rhodnius prolixus and anopheles stephensi, the natural vectors of human trypanosomiasis and malaria respectively, and in the snail biomphalaria glabrata, a natural invertebrate intermediate host of human schistosomiasis. therefore, no limits trypanosoma, plasmodium, and schistosoma development at all stages of the parasit ... | 2002 | 12049194 |
| effects of gamma irradiation on the development of trypanosoma rangeli in the vector rhodnius prolixus. | studies on the effects of gamma radiation on the infectivity of trypanosoma rangeli (strain h14) for the vector rhodnius prolixus revealed that (i) the ld(50) (lethal dose for 50% of bugs) for uninfected insects was 4147 rads; (ii) irradiated insects with a dose of 1200 rads subsequently infected with the flagellates exhibited a mortality of 45%, while uninfected irradiated insects showed a mortality of 5%, and infected nonirradiated insects exhibited 10% mortality; (iii) flagellates were presen ... | 2002 | 12095237 |
| dynamic development of trypanosoma cruzi in rhodnius prolixus: role of decapitation and ecdysone therapy. | decapitation and ecdysone therapy on the population dynamics of the trypanosoma cruzi dm28c clone in the stomach, small intestine and rectum of fifth-instar larvae of rhodnius prolixus were investigated. parasites were not found in the small intestine and rectum of decapitated insects after 10 days post-infection (p.i.). decapitated ecdysone-supplemented insects sustained the flagellate infection in both gut compartments. in the rectum, the population density of parasites increased 5-fold in ecd ... | 2002 | 12107464 |
| identification and distribution of carbohydrate moieties on the salivary glands of rhodnius prolixus and their possible involvement in attachment/invasion by trypanosoma rangeli. | in the present study, fitc-labelled lectins (wga, con a, pna, hpa, and tpa) were utilized to investigate carbohydrate residues on the surface of rhodnius prolixus salivary glands. the results revealed that the salivary glands are rich in carbohydrate moieties and the diversity in binding pattern of particular lectins showed the presence of specific carbohydrate residues in the basal lamina, muscle, and cell layers of the glands. subsequently, the sugars detected on the salivary gland surface wer ... | 2002 | 12128049 |
| the impact of chagas disease control in latin america: a review. | discovered in 1909, chagas disease was progressively shown to be widespread throughout latin america, affecting millions of rural people with a high impact on morbidity and mortality. with no vaccine or specific treatment available for large-scale public health interventions, the main control strategy relies on prevention of transmission, principally by eliminating the domestic insect vectors and control of transmission by blood transfusion. vector control activities began in the 1940s, initiall ... | 2002 | 12219120 |
| kdna markers define two major trypanosoma rangeli lineages in latin-america. | trypanosoma rangeli is a hemoflagellate parasite of man, domestic and wild animals in central and south america. the genus rhodnius is particularly susceptible to infection by t. rangeli and transmission by salivary inoculation has been demonstrated in 12 of 14 nominal species of naturally and experimentally infected insects. this report describes the molecular characterization of 37 strains of t. rangeli isolated from vertebrate and invertebrate hosts. strains were analyzed by hybridization wit ... | 2002 | 11755434 |
| rhodnius heme-binding protein (rhbp) is a heme source for embryonic development in the blood-sucking bug rhodnius prolixus (hemiptera, reduviidae). | we have previously shown that rhodnius prolixus' eggs and hemolymph are pink due to the presence of the hemeprotein rhodnius heme-binding protein (rhbp). in the hemolymph it functions as an antioxidant. nevertheless, its function in eggs has not been determined. here we present evidence that rhbp is a source of heme for embryonic development. rhbp content decreases during embryogenesis, but the total heme content of eggs remains unchanged. biliverdin, the product of heme degradation, is not dete ... | 2002 | 11886770 |
| incidence of trypanosoma cruzi infection in two guatemalan communities. | the prevalence of human infection by trypanosoma cruzi was assessed using an enzyme-linked immunosorbent assay (elisa) in a serological survey in 1998 of 2 rural communities (smh and ps) in guatemala. in smh (department of zacapa), where rhodnius prolixus was the principal vector, the seroprevalence amongst 373 people tested was 38.8%. in ps (department of santa rosa), where the main vector was triatoma dimidiata, 8.9% of the 428 people tested were seropositive. the overall prevalence of seropos ... | 2002 | 11925991 |
| a reinvestigation of brindley's gland exocrine compounds of rhodnius prolixus (hemiptera: reduviidae). | a chemical, electrophysiological and behavioral study was carried out to analyze the volatile compounds of the brindley's gland of rhodnius prolixus stål. six compounds were found in the brindley's gland of males and females: acetic, isobutyric, caproic acids and three compounds not identified. the mass spectra of the unidentified compounds have the appearance of a propionate ester, a butyrate ester and a valerate ester. there was no difference in the concentration of these compounds in the glan ... | 2002 | 11931024 |
| lack of manipulation of rhodnius prolixus (hemiptera: reduviidae) vector competence by trypanosoma cruzi. | behavioral implications of trypanosoma cruzi chagas infection in rhodnius prolixus stål were observed. feeding and defecation behaviors of infected versus uninfected insects were assessed on an artificial membrane-feeding system and on live guinea pigs. based on a defecation index, fifth instars were the most efficient vectors, followed by adult females, fourth instars, and adult males. bugs fasted for longer periods (5-6 mo) took smaller blood meals but defecated significantly earlier than bugs ... | 2002 | 11931271 |
| characterization of lipophorin binding to the fat body of rhodnius prolixus. | in insects, lipids are transported by a hemolymphatic lipoprotein, lipophorin. the binding of lipophorin to the fat body of the hematophagous insect rhodnius prolixus was characterized in a fat body membrane preparation, obtained from adult females. for the binding assay, purified lipophorin was radiolabelled in the protein moiety (125i-hdlp), and it was shown that iodination did not affect the affinity of the membrane preparation for lipophorin. under incubation conditions used, lipophorin bind ... | 2002 | 12530208 |
| parasite polymorphism may serve to enhance fitness in different host environments. | phenotypic expression of trans-sialidase (ts) by trypanosoma cruzi (silvio strain) is restricted to a subpopulation (20-30%) of broad trypomastigotes (ts+ parasites), while the larger subpopulation of slender trypomastigotes lacks ts expression (ts- parasites). rhodnius prolixus nymphs were infected with fractionated t. cruzi parasite populations (silvio strain). bugs ingesting ts- parasites produced significantly higher parasite loads than bugs ingesting either ts+ parasites or unfractionated p ... | 2002 | 12656128 |
| on the biosynthesis of rhodnius prolixus heme-binding protein. | the biosynthesis of rhodnius prolixus heme-binding protein (rhbp), which is present in the hemolymph and oocytes of rhodnius prolixus, was investigated. fat bodies of female insects incubated in vitro with 14c-leucine were able to synthesize and secrete 14c-rhbp to the culture medium. titrtion of synthesized rhbp with hemin showed that the protein secreted by the fat bodies is bound to heme, despite the presence of apo-rhbp in the hemolymph. the sequence of the rhbp cdna encodes a pre-protein of ... | 2002 | 12530221 |
| ion physiology of vitellogenic follicles. | the ion physiology of vitellogenic follicles from a lepidopteran (hyalophora cecropia) and a hemipteran (rhodnius prolixus) are compared. similarities that can be expected to occur in vitellogenic follicles of many other insects include: (1) gap junctions, which unite the cells of a follicle into an integrated electrical system, (2) transmembrane k(+) and h(+) gradients that account for over 60% of follicular membrane potentials, (3) absence of a cl(-) potential, (but the opening of channels to ... | 2002 | 12770038 |
| the role of eicosanoids on rhodnius heme-binding protein (rhbp) endocytosis by rhodnius prolixus ovaries. | the participation of eicosanoids and second messengers on the regulation of rhbp endocytosis by the ovaries was investigated, using [(125)i]rhbp in experiments in vivo and in vitro. addition of pge(2) (one of the products of the cyclooxygenase pathway) decreased in vitro the uptake of rhbp by 35%. the rate of rhbp endocytosis increased in the presence of indomethacin, a potent cyclooxigenase inhibitor, up to 50% in vitro and up to 55% in vivo, thus giving support to the role of cyclooxygenase de ... | 2002 | 11891130 |
| biochemical and functional characterization of recombinant rhodnius prolixus platelet aggregation inhibitor 1 as a novel lipocalin with high affinity for adenosine diphosphate and other adenine nucleotides. | the rhodnius prolixus aggregation inhibitor 1 (rpai-1) is a novel blood-sucking salivary molecule that binds to adp and attenuates platelet aggregation. in this report, we determine the binding constants and specificity of rpai-1 for adenine nucleotides and its functional significance. by the hummel-dreyer method of equilibrium gel filtration, we show that rpai-1 binds adp with a k(0.5) of 48.6 plus minus 12.2 nm. rpai-1 also displays high-affinity binding to atp, amp, ado, ap4a, and alpha,beta ... | 2002 | 11888300 |
| evidence for crf-like and kinin-like peptides as neurohormones in the blood-feeding bug, rhodnius prolixus. | in rhodnius prolixus, the rapid post-feeding diuresis is under neurohormonal control. while serotonin has been demonstrated to be a diuretic neurohormone [j exp biol 156 (1991) 557], a peptide is also known to be involved. previously, we have demonstrated the presence of corticotropin releasing factor (crf)-like and kinin-like peptides in the central nervous system (cns) of 5th instar rhodnius [j exp biol 202 (1999) 2017; peptides 22 (2001) 161]. these peptides are present in neurohemal sites of ... | 2002 | 12431735 |
| aggregation behaviour and interspecific responses in rhodnius prolixus stål. | the response to intra- and interspecific faecal assembling signals was tested in rhodnius prolixus. papers impregnated with excrement of r. prolixus induced the aggregation of larvae of this species, but also of those of triatoma infestans. however, faeces belonging to t. infestans were not able to assemble larvae of r. prolixus. on the other hand, there was no response of r. prolixus to putative chemical factors from their cuticle (footprints), in contrast to t. infestans. results are discussed ... | 2002 | 12118293 |
| oocyte fertilization triggers acid phosphatase activity during rhodnius prolixus embryogenesis. | acid phosphatase activity, previously identified in rhodnius prolixus oocytes, was studied during egg development. fertilized eggs exhibited a five fold increase of total acid phosphatase activity during the first days of development. in contrast non-fertilized oviposited eggs showed no activation of this enzyme. an optimum ph of 4.0 for pnpp hydrolysis in a saturable linear reaction and a strong inhibition by lysosomal acid phosphatase inhibitors such as naf (10 mm) and na(+)/k(+) tartrate (0.5 ... | 2002 | 12110294 |
| cyclic nucleotide-independent phosphorylation of vitellin by casein kinase ii purified from rhodnius prolixus oocytes. | in this study we show that vitellin (vt) phosphorylation in chorionated oocytes of rhodnius prolixus is completely inhibited by heparin (10 microg/ml), a classical casein kinase ii (ck ii) inhibitor. vt phosphorylation is not affected by modulators of cyclic nucleotide-dependent protein kinases such as c-amp (10 microm), h-8 (1 microm) and h-89 (0.1 microm). we have obtained a 3000-fold vt-free enriched preparation of ck ii. autophosphorylation of this enzyme preparation in the presence of (32)p ... | 2002 | 12110292 |
| rhodnius prolixus vitellin is composed of three different populations: comparison with vitellogenin. | rhodnius prolixus oocyte extracts were chromatographed on an ion exchange column in order to purify vitellin (vt). three vt heterogeneous populations were identified and named vt(1), vt(2), and vt(3) according to their order of elution from the column. the phosphate content of each population was determined, after lipid extraction, and a heterogeneous distribution was found: vt(1) being the less phosphorylated (50 mol p/mol protein) and vt(3) the heavily phosphorylated population (281 mol p/mol ... | 2002 | 12044487 |
| intracellular ion activities in malpighian tubule cells of rhodnius prolixus: evaluation of na+-k+-2cl- cotransport across the basolateral membrane. | intracellular ion activities (a(ion)) and basolateral membrane potential (vbl) were measured in malpighian tubule cells of rhodnius prolixus using double-barrelled ion-selective microelectrodes. in saline containing 103 mmol l(-1) na+, 6 mmol l(-1) k+ and 93 mmol l(-1) cl-, intracellular ion activities in unstimulated upper malpighian tubules were 21, 86 and 32 mmol l(-1), respectively. in serotonin-stimulated tubules, acl was unchanged, whereas ana increased to 33 mmol l(-1) and ak declined to ... | 2002 | 12000809 |
| contractions associated with the salivary glands of the blood-feeding bug, rhodnius prolixus: evidence for both a neural and neurohormonal coordination. | the salivary glands of the blood-feeding bug, rhodnius prolixus, are composed of a single epithelial layer of binucleate cells and a double layer of visceral muscle cells surrounding a large secretory cavity. the saliva contains substances which counteract the hemostasis of the host, and injection of saliva into the host is an essential component of successful and efficient gorging. the muscles surrounding the salivary glands of rhodnius are under polyneuronal control from the salivary nerve pro ... | 2002 | 11897388 |
| the biological activity of diuretic factors in rhodnius prolixus. | the rapid post-feeding diuresis of rhodnius prolixus is under neurohormonal control and involves the integrated activity of the crop, malpighian tubules and hindgut. one of the factors which is involved in this rapid diuresis is serotonin, however a peptide(s) is also considered to be involved. in other insects, corticotropin releasing factor (crf)-like and kinin-like, calcitonin-like peptides and cap(2b) have been demonstrated to be diuretic factors/hormones. in the present study, serotonin and ... | 2002 | 11897386 |
| wing shape divergence between rhodnius prolixus from cojedes (venezuela) and rhodnius robustus from mérida (venezuela). | the existence of rhodnius robustus as a species distinct from rhodnius prolixus has long been the main epidemiological question about chagas disease transmission in venezuela and surrounding countries. these two taxa are morphologically and genetically very similar, but only r. prolixus is assumed to colonize houses and transmit chagas disease to humans. r. robustus is assumed to be an exclusively sylvatic species, restricted to palm trees. if robustus and prolixus are actually the same species, ... | 2002 | 12797988 |
| hydrocarbons of rhodnius prolixus, a chagas disease vector. | the surface hydrocarbons of the blood-sucking insect, rhodnius prolixus, a major chagas disease vector in venezuela, colombia and central america, were characterized by capillary gas chromatography coupled to mass spectrometry (cgc-ms). a total of 54 single or multicomponent peaks of saturated, straight-chain and methyl-branched hydrocarbons were identified. major n-alkanes were n-c27, n-c29, n-c31 and n-c33 hydrocarbons. in the branched fraction, methyl groups were at positions 3, 5, 7, 11, 13, ... | 2001 | 11435128 |
| third instar nymphs of rhodnius prolixus exposed to alpha-cyanopyrethroids: from hyperactivity to death. | the hyperactivity, incoordination, recovery, and mortality produced by four alpha-cyanopyrethroids usually used for chagas disease vector control (beta-cypermethrin, beta-cyfluthrin, lambda-cyhalothrin, and deltamethrin) were evaluated on third instar nymphs of rhodnius prolixus. all pyrethroids modified the locomotor activity of the nymphs, which increased linearly as a function of the log of insecticide concentration. lambda-cyhalothrin showed the lowest values of effective concentration 50%, ... | 2001 | 11276069 |
| comparison of disturbance stridulations in five species of triatominae bugs. | it has been observed that triatoma infestans and rhodnius prolixus females stridulate to reject copulatory attempts performed by males. in addition, triatomines stridulate when disturbed or handled. in the present study, the temporal structure and frequency spectra of vibrational signals produced by mechanically disturbed t. infestans, t. sordida, t. guasayana, r. prolixus and dipetalogaster maxima were analysed and compared. the inter-ridge distances of the prosternal stridulatory organ of the ... | 2001 | 11369310 |
| fluid secretion in rhodnius upper malpighian tubules (umt): water osmotic permeabilities and morphometric studies. | we have measured the osmotic permeability of the basolateral cell membrane (poscb) and compared it with the transepithelial permeability (poste) to calculate the paracellular (posp) permeability of the upper malpighian tubules (umt) of the 5th instar of rhodnius prolixus under several experimental conditions, namely, at rest and after stimulation to secrete with 5-ht, each under control conditions (no treatment), after treatment with pcmbs, and after addition of pcmbs and dtt. secretion rate is ... | 2001 | 11891553 |
| sulfated glycosaminoglycans from ovary of rhodnius prolixus. | we have characterized sulfated glycosaminoglycans from ovaries of the blood-sucking insect rhodnius prolixus, and determined parameters of their synthesis and distribution within this organ by biochemical and histochemical procedures. the major sulfated glycosaminoglycan is heparan sulfate while chondroitin 4-sulfate is a minor component. these glycosaminoglycans are concentrated in the ovarian tissue and are not found inside the oocytes. besides this, we detected the presence of a sulfated comp ... | 2001 | 11102832 |
| resonance raman spectroscopic study of nitrophorin 1, a nitric oxide-binding heme protein from rhodnius prolixus, and its nitrosyl and cyano adducts. | the resonance raman (rr) spectra of nitrophorin 1 (np1) from the saliva of the blood-sucking insect rhodnius prolixus, in the absence and presence of nitric oxide (no) and in the presence of cyanide (cn(-)), have been studied. the np1 displayed rr spectra characteristic of six-coordinate high-spin (6chs) ferric heme at room temperature and six-coordinate low-spin heme (6cls) at low temperature (77 k). no and cn(-) each bind to fe(iii), both ligands forming 6cls complexes with np1. the fe(iii)-no ... | 2001 | 11716723 |
| a quantum chemical survey of metalloporphyrin-nitrosyl linkage isomers: insights into the observation of multiple feno conformations in a recent crystallographic determination of nitrophorin 4. | using density functional theory-based geometry optimizations, we have searched for eta(1)-no, eta(1)-on (isonitrosyl), and eta(2)-no (side-on bound no) linkage isomers of a number of metalloporphyrin-no complexes, m(por)(no)(l), where por = porphinato dianion, m = mn(ii), fe(ii), fe(iii), ru(ii), ru(iii), co(ii), and rh(ii), and l = no ligand, sme, ph, and imidazole. the eta(1)-no isomer had the lowest energy in all cases, and the isonitrosyl isomer was also located as a higher energy potential ... | 2001 | 11403599 |
| [bioactive molecule supporting blood feeding: unique activities from the salivary glands in the kissing bug, rhodnius prolixus]. | 2001 | 11268644 | |
| the distribution of a kinin-like peptide and its co-localization with a crf-like peptide in the blood-feeding bug, rhodnius prolixus. | rhodnius prolixus, a blood-feeding hemipteran insect, ingests large meals which are followed by rapid diuresis to eliminate excess water and salt. in rhodnius, serotonin and an unidentified peptide(s) [33,34] have been shown to act as neurohormonal diuretic factors. in other insects, two families of diuretic peptides, the corticotropin releasing factor (crf)-like, and kinin peptides [9], have been identified and sequenced. recently, we demonstrated the presence of a crf-like diuretic peptide in ... | 2001 | 11179809 |
| transepithelial potential in malpighian tubules of rhodnius prolixus: lumen-negative voltages and the triphasic response to serotonin. | previous studies of the malpighian tubules of rhodnius reported lumen-negative values of transepithelial potential (tep), and a characteristic triphasic change in tep in response to stimulation of tubule fluid secretion by serotonin. tep was measured using the ramsay technique, in which electrodes are positioned in bathing and secreted fluid droplets for tubules isolated under paraffin oil. the validity of this method of tep measurement has been questioned on the grounds that, in tubules of some ... | 2001 | 11166306 |
| [effect of human blood feeding on the fecundity, fertility and biological cycle of rhodnius prolixus (hemiptera: reduviidae)]. | the effect of several human blood fractions artificially fed to rhodnius prolixus stal 1859 on oviposture (fecundity), egg-hatching (fertility) and life cycle was observed. specimens fed on man's blood were more fecund than those fed with woman's blood. there were no significant differences in fertility related to host sex. the nymphal development time and number of feedings to molt to the following instar were estimated. animals fed only on blood plasm did not finish nymphal development, while ... | 2001 | 11935922 |
| [feeding and defecation of rhodnius (hemiptera: reduviidae) fed human blood]. | feeding and defecation behavior of rhodnius prolixus stal, 1859, r. robustus larrousse, 1927, r. neivai lent, 1953 and r. pictipes stal, 1872, artificially fed on human blood, were studied under laboratory conditions. in all species, first instar nymphs did not defecate in the first 30 minutes after feeding. r. pictipes did not accept artificial feeding but fed directly on humans. nymph and adult r. prolixus had a higher defecation index (di) than other species; third instar nymphs had the highe ... | 2001 | 11935923 |
| movement of rhodnius prolixus (hemiptera: reduviidae) within a simulated house environment. | we observed the movement, attraction, and resting behavior of laboratory rhodnius prolixus stål within a house environment, simulated by a styrofoam box. movement of r. prolixus into various refuge types (fiberpots or white-, cream-, or black-colored modified gomez-nunez boxes) at different strata was assessed. greater numbers of fifth instars sought a refuge than third instars. fasted nymphs sought a refuge more than fed nymphs. our simulated house environment showed potential as a laboratory a ... | 2001 | 11761381 |
| differentiation and genetic analysis of rhodnius prolixus and rhodnius colombiensis by rdna and rapd amplification. | domiciliated rhodnius prolixus and sylvatic r. colombiensis were analyzed in order to confirm their genetic divergence and verify the risk that the latter represents in the domiciliation process, and to provide tools for identifying the sources of possible reinfestation by triatomines in human dwellings allowing control programs to be undertaken. comparison of random amplified polymorphic dna amplification patterns and cluster analysis suggests reproductive discontinuity between the two species. ... | 2001 | 11784920 |
| characterization of a cdna encoding a cathepsin l-like protein of rhodnius prolixus. | the interaction of rhodnius prolixus digestive enzymes with trypanosoma cruzi could be important for parasite survival. we report herein the complete sequence of the messenger of a cathepsin l-like molecule (rpcat). the cdna has 5'- and 3'- end utrs and a methionine codon that corresponds likely to a translation initiation codon. in the deduced amino acid sequence, a region corresponding to an erfinin domain, diagnostic of l-cathepsins, and a possible pro-peptide cleavage site were observed. at ... | 2001 | 11881815 |
| ligand-induced heme ruffling and bent no geometry in ultra-high-resolution structures of nitrophorin 4. | the nitrophorins are a family of proteins that use ferric heme to transport nitric oxide (no) from the salivary glands of blood-sucking insects to their victims, resulting in vasodilation and reduced blood coagulation. we have refined atomic resolution structures of nitrophorin 4 (np4) from rhodnius prolixus complexed with no (1.08 a) and nh(3) (1.15 a), yielding a highly detailed picture of the iron coordination sphere. in np4-no, the no nitrogen is coordinated to iron (fe-n distance = 1.66 a) ... | 2001 | 11560480 |
| hydrogen peroxide detoxification in the midgut of the blood-sucking insect, rhodnius prolixus. | here we investigated h2o2 production and detoxification in the hematophagous hemiptera, rhodnius prolixus. superoxide dismutase (sod) catalyzes the dismutation of superoxide radical (o2-). this reaction produces hydrogen peroxide, which is scavenged by antioxidant enzymes such as catalase (cat). sod and cat activities were found in all tissues studied, being highest in the midgut. cat was dose-dependently inhibited in vivo by injections of 3-amino-1,2,4-triazole (at). insects treated with at sho ... | 2001 | 11568965 |
| cytoskeleton elements mediate the inhibition of the (na++k+)atpase activity by pkc in rhodnius prolixus malpighian tubules during hyperosmotic shock. | in a previous paper, we observed that the specific activity of (na++k+)atpase of the isolated malpighian tubules from rhodnius prolixus is inhibited by protein kinase c (pkc) during hyperosmotic shock [arenstein et al., j membr biol 146:47-57 [1995]; caruso-neves et al., z naturforsch 53c:911-917 [1998]). in the present paper, we study the involvement of the cytoskeleton in this process using isolated malpighian tubules of rhodnius prolixus. we observed that pre-incubation of the malpighian tubu ... | 2001 | 11568967 |
| mitochondrial dna sequences of triatomines (hemiptera: reduviidae): phylogenetic relationships. | the phylogenetic relationships among 18 species of triatominae were inferred based on mitochondrial dna (mtdna) sequences. the species of triatoma included 11 belonging to the infestans complex [t. infestans (klug), t. guasayana wygodzinsky & abalos, t. sordida (stål), t. platensis neiva, t. brasiliensis neiva, t. rubrovaria (blanchard), t. vitticeps (stål), t. delpontei romaña & abalos, t. maculata (erichson), t. patagonica del ponte, and t. matogrossensis leite & barbosa] and four others of th ... | 2001 | 11580040 |
| seroprevalence of human trypanosoma cruzi infection in diferent geografic zones of chiapas, mexico. | a serologic survey was carried out in four different geographic zones of chiapas, mexico. a total of 1,333 samples were collected from residents of thirteen communities located on the coast, central mountain, lacandon forest and a zone called mesochiapas. one hundred and fifty one seropositive individuals (11.3%) were identified. human trypanosoma cruzi infection was influenced by geography. in the lacandon forest and central mountains there was a higher seroprevalence 32.1 and 13.8% respectivel ... | 2001 | 11600911 |
| an electron microscopic study of penetration by trypanosoma rangeli into midgut cells of rhodnius prolixus. | the process of interaction of the choachi strain of trypanosoma rangeli with intestinal epithelial cells of rhodnius prolixus was analyzed in experiments carried out in vitro and in vivo. for the in vitro experiments small fragments of the anterior region of the posterior midgut were incubated in the presence of the parasites, fixed, and processed for observation with the scanning electron microscope. parasites attached to the surface of some epithelial cells, especially to the extracellular mem ... | 2001 | 11161989 |
| heme biosynthesis and oogenesis in the blood-sucking bug, rhodnius prolixus. | we have previously shown that the pathway of porphyrin synthesis operates in the blood feeding triatomine bug rhodnius prolixus but not in the cattle tick boophilus microplus. in the present paper we studied the correlation between heme synthesis and egg development in rhodnius. there is a sharp increase heme biosynthetic capability in the fat body (160%) and in the ovaries (360%) in response to a blood meal, as evaluated from the activity of the enzyme delta-aminolevulinate dehydratase (ec 4.2. ... | 2001 | 11222945 |
| interrupting chagas disease transmission in venezuela. | the interruption of vectorial transmission of chagas disease in venezuela is attributed to the combined effects of ongoing entomoepidemiological surveillance, ongoing house spraying with residual insecticides and the concurrent building and modification of rural houses in endemic areas during almost five decades. the original endemic areas which totaled 750,000 km(2), have been reduced to 365,000 km(2). during 1958-1968, initial entomological evaluations carried out showed that the house infesta ... | 2001 | 11246282 |
| purification and characterization of a lipid transfer particle in rhodnius prolixus: phospholipid transfer. | in this study we report the purification and characterization of a lipid transfer particle (ltp) from rhodnius prolixus hemolymph, and its participation in phospholipid and diacylglycerol transfer processes. (3)h-diacylglycerol labeled low density lipophorin from manduca sexta ((3)h-ldlp) was incubated with r. prolixus lipophorin (lp) in the presence of rhodnius hemolymph. following incubation and isolation, both lipoproteins showed equivalent amounts of (3)h-labeled lipids. hemolymph was subjec ... | 2001 | 11267895 |
| bacterial symbiosis and paratransgenic control of vector-borne chagas disease. | the triatomine vectors of chagas disease are obligate haematophagous insects, feeding on vertebrate blood throughout their entire developmental cycle. as a result of obtaining their nutrition from a single food source, their diet is devoid of certain vitamins and nutrients. consequently, these insects harbour populations of bacterial symbionts within their intestinal tract, which provide the required nutrients that are lacking from their diet. we have isolated and characterised symbiont cultures ... | 2001 | 11334952 |
| differential susceptibility of triatomines of the genus rhodnius to trypanosoma rangeli strains from different geographical origins. | the susceptibility of four rhodnius species to different trypanosoma rangeli strains was evaluated using both intracoelomic inoculation and oral infection. rhodnius prolixus, rhodnius domesticus, rhodnius neglectus and rhodnius nasutus were infected with trypanosoma rangeli macias (venezuela), choachi (colombia) and sc-58 (brazil) strains, revealing distinct haemolymph and salivary glands infection rates. the obtained infection rates were revealed to be dependent on the method of infection and t ... | 2001 | 11334954 |
| identification of a new water channel (rp-mip) in the malpighian tubules of the insect rhodnius prolixus. | malpighian tubules (mt) of rhodnius prolixus transport fluid at very high rates. to identify whether aquaporins (aqps) are present in the mt of r. prolixus, total ribonucleic acid (rna) was isolated from mt and used in a reverse transcription, polymerase chain reaction (rt-pcr), with two degenerate primers to highly conserved regions of the members of the aqps family. a deoxyribonucleic acid (dna) fragment of 370 bp was amplified; its sequence revealed a novel protein, representing a new member ... | 2001 | 11374065 |
| comparison of polymerase chain reaction on fresh tissue samples and fecal drops on filter paper for detection of trypanosoma cruzi in rhodnius prolixus. | pcr detection of trypanosoma cruzi in rhodnius prolixus using fresh tissue or fecal drops on filter paper showed comparable results: 38.7% infection rate using the fresh tissue sample and 37.9% by dried fecal drop. | 2001 | 11391422 |
| role of superoxide and reactive nitrogen intermediates in rhodnius prolixus (reduviidae)/trypanosoma rangeli interactions. | this study compares aspects of the superoxide, nitric oxide and prophenoloxidase pathways in rhodnius prolixus hemolymph, measured in parallel, in response to trypanosoma rangeli inoculation. responses to two strains of t. rangeli, and two developmental forms, were studied, and the results obtained were correlated with the ability of the parasites to survive, multiply, and complete their life cycles in the hemolymph of the host. t. rangeli h14 strain parasites, which fail to complete their life ... | 2001 | 11426951 |
| testis ecdysiotropin, an insect gonadotropin that induces synthesis of ecdysteroid. | testes of lepidoptera synthesized ecdysteroid in a somewhat different temporal pattern than the prothoracic glands that release ecdysteroid to the hemolymph. brain extracts from heliothis virescens and lymantria dispar induced testes to synthesize ecdysteroid, but did not affect prothoracic glands. the testis ecdysiotropin (lte) was isolated from l. dispar pupal brains by a series of high-pressure chromatography steps. its sequence was ile-ser-asp-phe-asp-glu-tyr-glu-pro-leu-asn-asp-ala-asp-asn- ... | 2001 | 11462222 |
| assessment of hepatitis b virus dna and hepatitis c virus rna in the common bedbug (cimex lectularius l.) and kissing bug (rodnius prolixus). | historical clinical studies suggest the potential for insect-borne transmission of human hepatitis viruses. studies of hepatitis b virus (hbv) persistence in insects were performed before the advent of molecular techniques, and studies to assess possible insect-borne transmission of hepatitis viruses have not yet been performed. the aim of this study was to determine, using molecular techniques, whether hbv and hepatitis c virus (hcv) persist in and are excreted in the feces of the bedbug cimex ... | 2001 | 11467652 |
| crystallization and preliminary x-ray study of haem-binding protein from the bloodsucking insect rhodnius prolixus. | rhodnius haem-binding protein (rhbp) from the bloodsucking insect rhodnius prolixus, a 15 kda protein, has been crystallized using polyethylene glycol as a precipitant. x-ray diffraction data have been collected at a synchrotron source. the crystals belong to the space group p4(1(3))2(1)2, with unit-cell parameters a = b = 64.98, c = 210.68 a, and diffract beyond 2.6 a resolution. | 2001 | 11375508 |
| proteolytic activation of canatoxin, a plant toxic protein, by insect cathepsin-like enzymes. | canatoxin is a protein isolated from jackbean (canavalia ensiformis), seeds. injected intraperitoneally, the toxin is lethal to mice but it is inactive if given orally. canatoxin is also lethal when fed to insects with cathepsin-based digestion while insects with trypsin-based digestion are not affected. the hypothesis that canatoxin is proteolytically activated by cathepsins was investigated. experiments were performed with 4(th) instar and adult rhodnius prolixus fed meals containing canatoxin ... | 2000 | 10918311 |
| topographical variations in the structure of the smooth septate junction. | smooth septate junctions in the midgut of musca domestica and in malpighian tubules of both musca and rhodnius prolixus are described. details of the structures revealed after standard fixation, fixation in the presence of the stain, lanthanum hydroxide, and after freeze-fracture are discussed in the light of models previously put forward to explain the interrelations of the images obtained by these different methods. the organization of the junction between cells of the midgut varies in the api ... | 2000 | 90053 |
| amplification of a specific repetitive dna sequence for trypanosoma rangeli identification and its potential application in epidemiological investigations. | trypanosoma rangeli can infect humans as well as the same domestic and wild animals and triatomine vectors infected by trypanosoma cruzi in central and south america. this overlapping distribution complicates the epidemiology of american trypanosomiasis due to the cross-reactivity between t. rangeli and t. cruzi antigens and the presence of conserved dna sequences in these parasites. we have isolated a t. rangeli-specific dna repetitive element which is represented in approximately 103 copies pe ... | 2000 | 11162365 |
| serial heart rate changes in rats inoculated by conjunctival instillation of trypanosoma cruzi obtained from bug faeces. | the cardiac effects of experimentally induced myocarditis, when the parasite is obtained from mouse blood, are well known. however, the consequences of the infection when the parasites are obtained from bug faeces are less well defined. in the present investigation, we have used the "y" strain of trypanosoma cruzi, which was maintained in rhodnius prolixus by repeated passages in mice. the faeces of 30 infected bugs were collected, the number of parasites counted and 4,000 parasites inoculated b ... | 2000 | 11175582 |
| [natural trypanosoma cruzi infection of triatominae bugs associated with human habitations in mexico ]. | to estimate the prevalence of infection with trypanosoma cruzi in triatominae species frequently found in and around mexican dwellings, and to assess the frequency of triatominae in towns by state. | 2000 | 11201577 |
| phylogeny and molecular taxonomy of the rhodniini derived from mitochondrial and nuclear dna sequences. | eleven species of rhodnius and one of psammolestes were compared by dna sequence analysis of fragments of the mitochondrial large subunit ribosomal rna (mtlsurrna), the mitochondrial cytochrome b (mtcytb), and the d2 variable region of the 28s nuclear rna (d2), totaling 1,429 base pairs. the inferred phylogeny, using triatoma infestans as an outgroup, revealed two main clades within the rhodniini--one, including the prolixus group of species (rhodnius prolixus, rhodnius robustus, rhodnius neglec ... | 2000 | 11220761 |
| inter-specific and developmental differences on the array of antennal chemoreceptors in four species of triatominae (hemiptera: reduviidae). | the aim of the work was to investigate the pattern of chemoreceptor sensilla in adults and fifth stage nymphs of rhodnius prolixus, r. neglectus, triatoma infestans and t. sordida in order to study differences and similarities between genera and species. three types of sensilla were analyzed by light microscopy: thin-walled trichoidea, thick-walled trichoidea and basiconica. the number of sensilla of each three types were counted. the length of the antennal segments were also used as a variable ... | 2000 | 10656707 |
| haematophagy and cleptohaematophagy of clerada apicicornis (hemiptera: lygaeidae), a potential biological control agent of rhodnius prolixus (hemiptera: reduviidae). | because of its ability to prey on triatominae in rural houses, clerada apicicornis has been suggested as a potential biological control agent of rhodnius prolixus. it has also been suggested as a potential vector of mammalian trypanosomes such as trypanosoma cruzi, because of its ability to take blood directly from mammals. to help resolve these conflicting ideas, we assessed the haematophagic behaviour of c. apicicornis by carrying out feeding trials on laboratory animals. cleptohaematophagic b ... | 2000 | 10656719 |
| the ability of rhodnius prolixus (hemiptera; reduviidae) to approach a thermal source solely by its infrared radiation. | the ability of the haematophagous bug rhodnius prolixus to approach a pure ir source only by its long-wave infrared radiation (ir) was investigated. to exclude any heated air from reaching the bug a cooled ir-transmitting window was placed between the ir-source (a peltierelement heated to 35 degrees c) and the bug. starved bugs were tested under invisible short-wave ir illumination (lambda<1 µm) in order to exclude also any visual cues. the number of bugs approaching the ir-source was significan ... | 2000 | 10742523 |
| effects of fluctuating moisture and temperature regimes on the infection potential of beauveria bassiana for rhodnius prolixus. | the effect of both moisture and temperature on the infective potential of beauveria bassiana to the chagas' disease vector, rhodnius prolixus, was studied under fluctuating regimes. at constant 25 degrees c, contaminated first-instar nymphs exposed to increasing daily periods of initial exposure to 97% rh, followed by transfer to reduced humidity (43, 53, 75, and 86% rh), showed a significant reduction in mortality when the 97% rh exposure time declined from 12 to 8 h per day. the duration of di ... | 2000 | 10753596 |
| distribution of domestic triatominae and stratification of chagas disease transmission in oaxaca, mexico. | mexico has 18 species of triatomine bugs (hemiptera: reduviidae) reported to be vectors of trypanosoma cruzi. chagas disease is widespread in mexico, with up to 3.5% seropositivity of human transfusion blood. the state of oaxaca has the longest history of endemic chagas disease, based on acute and chronic case reports, and of entomological surveys in the country. however, the state health care services need more information on current risks of vector transmission. in order to identify and charac ... | 2000 | 10759308 |
| insecticide resistance in brazilian triatoma infestans and venezuelan rhodnius prolixus. | resistance levels to insecticides used in control of chagas disease vectors were assessed in two species of bugs (hemiptera: reduviidae): triatoma infestans (klug) from brazil and rhodnius prolixus stål from venezuela. the resistance ratios, compared to susceptible laboratory strains, were determined by topical application bioassays. the t. infestans pa strain exhibited resistance ratios of 7x to deltamethrin, 3.6x to beta-cyfluthrin and 3.3x to cypermethrin, but was susceptible to beta-cypermet ... | 2000 | 10759312 |
| cleptohaematophagy of the triatomine bug belminus herreri. | the triatomine bug belminus herreri, previously known only from panama, is reported for the first time from colombia. three adult b. herreri were collected from a chicken coop and a viable egg was found on a bactris palm at carmen municipality in humid forest zone at 680 m altitude. from 44 eggs produced, five progeny were reared to adulthood. during early instars they were unable to take bloodmeals directly from vertebrate hosts, but they fed successfully by cleptohaematophagy on blood from rep ... | 2000 | 10759319 |
| purification, cloning, expression, and mechanism of action of a novel platelet aggregation inhibitor from the salivary gland of the blood-sucking bug, rhodnius prolixus. | rhodnius prolixus aggregation inhibitor 1 (rpai-1), a 19-kda protein isolated from the salivary gland of r. prolixus, was purified by strong cation exchange and reverse-phase high performance liquid chromatographies. based on 49 amino-terminal amino acid sequences of rpai-1, primers were produced to generate probes to screen an r. prolixus salivary gland cdna library. a phage containing the full-length clone of rpai-1 codes for a mature protein of 155 amino acids. rpai-1 shows sequence homology ... | 2000 | 10777556 |
| neural inhibition of the corpus allatum in the last larval instar differs from that in adults in the blood-feeding insect, rhodnius prolixus. | an active corpus allatum (ca) in the blood feeding insect, rhodnius prolixus, releases a substance that inhibits metamorphosis in larvae, and activates egg production in adults. in adults, transecting the nervus corporis cardiacum ii's (nccii), which are attached posteriorly to each protocerebral lobe, greatly increases egg production indicating that the adult ca is activated and receives neural inhibition from cells associated with the nccii [chiang, arch. insect. biochem. physiol. 39:126-131 ( ... | 2000 | 10790180 |
| haemozoin formation in the midgut of the blood-sucking insect rhodnius prolixus. | malaria parasites digest haemoglobin and detoxify the free haem by its sequestration into an insoluble dark-brown pigment known as haemozoin (hz). until recently, this pigment could be found only in plasmodium parasites. however, we have shown that hz is also present in the midgut of the blood-sucking insect rhodnius prolixus [oliveira et al. (1999) nature 400, 517-518]. here we show that hz synthesis in the midgut of this insect is promoted by a particulate fraction from intestine lumen. haem a ... | 2000 | 10899317 |
| nitrophorins and related antihemostatic lipocalins from rhodnius prolixus and other blood-sucking arthropods. | recent gene sequence and crystal structure determinations of salivary proteins from several blood-sucking arthropods have revealed an unusual evolutionary relationship: many such proteins derive their functions from lipocalin protein folds. many blood-sucking arthropods have independently evolved the ability to overcome a host organism's means of preventing blood loss (called hemostasis). most blood feeders have proteins that induce vasodilation, inhibit blood coagulation, and reduce inflammatio ... | 2000 | 11058753 |
| two different vibratory signals in rhodnius prolixus (hemiptera: reduviidae). | in this study the substrate-borne stridulatory vibrations produced by rhodnius prolixus females were recorded and analysed in two different behavioural contexts. in the context of sexual communication females spontaneously stridulated to reject copulatory attempts performed by males. these male-deterring stridulations were fully effective: out of 61 attempts, no copulation occurred. these stridulations consisted of short series of repetitive syllables, each one composed by a single chirp. in the ... | 2000 | 11114389 |
| high density of rhodnius prolixus in a rural house in colombia. | 2000 | 11127235 | |
| effects of lignoids on a hematophagous bug, rhodnius prolixus: feeding, ecdysis and diuresis. | the effects of lignoids on feeding, ecdysis and diuresis in fourth-instar larvae of rhodnius prolixus (hemiptera) were investigated. up to 100 microg/ml burchellin, podophyllotoxin, pinoresinol, sesamin, licarin a, or nordihydroguaiaretic acid (ndga) in the diet did not induce antifeedant effects. pinoresinol and ndga significantly inhibited ecdysis. in experiments in vivo, burchellin and podophyllotoxin reduced the production of urine after feeding. 5-hydroxytryptamine (5-ht), a diuretic hormon ... | 2000 | 11130672 |
| effects of some lignans and neolignans on the development and excretion of rhodnius prolixus. | the effects of six lignans and neolignans as inhibitors of ecdysis and on the water balance in fourth-instar larvae of rhodnius prolixus were studied by oral, topical and continuous contact treatments. the main results may be summarised as follows: (i) burchellin, pinoresinol, sesamin, licarin a and nordihydroguaiaretic acid (ndga) did not cause feeding inhibition at doses of 100 micrograms/ml blood; podophyllotoxin had no antifeedant effect but caused a high moulting inhibition and significant ... | 2000 | 11449462 |
| rhodnius prolixus: effects of the neolignan burchellin on in vivo and in vitro diuresis. | supplementation of blood with the neolignan burchellin (100 microg/ml), a compound from the arboreous lauraceae aniba burchelli, affected the course of excretion of fourth-instar larvae of rhodnius prolixus, especially directly after feeding, and reduced the volume of feces/urine excreted within 6 h of feeding to about 18% and, on the simultaneous addition of the diuretic hormone analogue 5-hydroxytryptamine (5-ht), about 71% of that observed in untreated bugs. in the latter, 5-ht induced a sign ... | 2000 | 11002977 |
| kinetics and equilibria in ligand binding by nitrophorins 1-4: evidence for stabilization of a nitric oxide-ferriheme complex through a ligand-induced conformational trap. | nitrophorins 1-4 (np1-4) are ferriheme proteins from the blood-sucking insect rhodnius prolixus that transport nitric oxide (no) to the victim, sequester histamine, and inhibit blood coagulation. here, we report kinetic and thermodynamic analyses for ligand binding by all four proteins and their reduction potentials. all four undergo biphasic association and dissociation reactions with no. the initial association is fast (1.5-33 microm(-)(1) s(-)(1)) and similar to that of elephant metmyoglobin. ... | 2000 | 10956000 |