Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the crystal structure of nitrophorin 4 at 1.5 a resolution: transport of nitric oxide by a lipocalin-based heme protein. | nitrophorins are nitric oxide (no) transport proteins from the saliva of blood-feeding insects, which act as vasodilators and anti-platelet agents. rhodnius prolixus, an insect that carries the trypanosome that causes chagas' disease, releases four no-loaded nitrophorins during blood feeding, whereupon the ligand is released into the bloodstream or surrounding tissue of the host. histamine, a signaling molecule released by the host upon tissue damage, is tightly bound by the nitrophorins; this m ... | 1998 | 9782054 |
| beauveria bassiana (hyphomycetes) as a possible agent for biological control of chagas disease vectors. | beauveria bassiana (balsamo) vuillemin (isolate cg306) was tested on 3rd instars of 9 triatoma spp., 4 rhodnius spp., 2 panstrongylus spp. and dipetalogaster maxima (uhler) at 25 degrees c and 50% rh. quantitative sporulation of the fungus on cadavers was studied at 25 degrees c and 97% rh. mortality, estimates of survival time, and conidial production on cadavers differed significantly among the genera and species tested. panstrongylus herreri wygodzinsky, dipetalogaster maxima, triatoma pictur ... | 1998 | 9835689 |
| salivary heme proteins distinguish rhodnius prolixus from rhodnius robustus (hemiptera: reduviidae: triatominae). | rhodnius prolixus interpopulation variability was studied based on a new approach using salivary heme proteins (nitrophorins) electrophoresis in starch gel. we compared salivary proteins profiles of r. prolixus from three different laboratory colonies from honduras, venezuela, brazil and rhodnius robustus from venezuela, constructing a upgma. the honduran and venezuelan populations could not be distinguished from each other, but the brazilian population was well separated from the others. the hi ... | 1998 | 9879737 |
| uptake of rhodnius heme-binding protein (rhbp) by the ovary of rhodnius prolixus. | the uptake of rhbp (rhodnius heme-binding protein) by the ovaries of rhodnius prolixus was characterized. rhbp purified from occyte was labeled with 125i and used to study the process of uptake by the ovary in vivo and in vitro. after injection, the [125i]rhbp was readily removed from the hemolymph and accumulated especially in the ovary. the capacity of the ovary to take up [125i]rhbp from the hemolymph varied during the days following blood meal. it increased up to day 2, remained stable until ... | 1998 | 9880903 |
| haemolymph and fat body metallo-protease associated with enterobacter cloacae infection in the bloodsucking insect, rhodnius prolixus. | analysis of zymograms with sds-polyacrilamide gel electrophoresis containing gelatin as substrate, and performed on samples of haemolymph or fat body taken from rhodnius prolixus inoculated or not with enterobacter cloacae, demonstrated distinct patterns of protease activities: (i) in the haemolymph two proteases were induced in insects inoculated with bacteria; (ii) two proteases were detected in the fat bodies derived from non-inoculated controls or insect inoculated with sterile culture mediu ... | 1998 | 9921310 |
| [wild vectors of chagas' disease in an urban area of manaus (am): flying activity during dry and rainy seasons]. | adults of rhodnius prolixus, r. pictipes and panstrongylus geniculatus found in houses in manaus have high rates of trypanosoma cruzi infection. rhodnius spp. were found throughout the year, but males of p. geniculatus were significantly more frequent in the dry season. | 1998 | 9477705 |
| random amplification of polymorphic dna as a tool for taxonomic studies of triatomine bugs (hemiptera: reduviidae). | eleven of 27 decameric primers were found to be suitable for random amplification of polymorphic dna (rapd) from triatomine bugs on the basis that they produced discrete profiles and distinguished among panstrongylus megistus (burmeister), rhodnius prolixus stål, and triatoma infestans (klug). the legs, or single leg segments, of individual bugs were used as the source of dna so that the taxonomic value of the bug was conserved. within the scope of the specimens studied, rapd profiles allowed as ... | 1998 | 9542343 |
| anti-diuresis in the blood-feeding insect rhodnius prolixus stål: antagonistic actions of camp and cgmp and the role of organic acid transport. | secretion of primary urine by upper malpighian tubules of the blood-sucking insect rhodnius prolixus has recently been shown to be inhibited by cyclic gmp (cgmp). in the present work, we have demonstrated that cgmp has effects antagonistic to those of camp in rhodnius tubules and have further characterized the effects of cgmp on tubular secretion. cyclic gmp inhibited secretion at all concentrations from 5x10(-6) to 10(-3)m, though this inhibition was partially or wholly reversed by large (2mm) ... | 1998 | 12769938 |
| role of the head in the ultrastructural midgut organization in rhodnius prolixus larvae: evidence from head transplantation experiments and ecdysone therapy. | studies on the effects of decapitation, head transplantation and ecdysone therapy on the ultrastructural organization of the midgut in 5th-instar larvae of rhodnius prolixus, were carried out. control insects had a typical and significant organization of the epithelial cells (mainly microvilli, extracellular membrane layers and basal portion of the epithelial cells) of the midgut (stomach and intestine) during the entire period of the experiment. however, the host larvae, when decapitated 1 day ... | 1998 | 12769937 |
| feeding is not necessary for triggering plasticization of the abdominal cuticle in haematophagous bugs. | a simple device was used to quantify changes in the mechanical properties of the cuticle of rhodnius prolixus and triatoma infestans that take place when these insects feed, i.e., plasticization. different stimuli were presented for 1min to test for their ability to trigger plasticization. these were: a blood meal, a ringer solution meal, contact with a warm surface and thermal stimulation without such contact. our results supplant any previous hypotheses that have supposed that the presence of ... | 1998 | 12770155 |
| comparative kinetics of bloodmeal intake by triatoma infestans and rhodnius prolixus, the two principal vectors of chagas disease. | chagas disease vector insects triatoma infestans and rhodnius prolixus (fifteen stage iii nymphs per 4 litre cage) were allowed to feed on anaesthetized mice for 1 h (control group), or on active non-anaesthetized mice (nam) for 2, 4 or 8 h exposure. the bloodmeal size (weight increase) for both species was proportional to the duration of contact with nam, due to ingestion of multiple small bloodmeals, up to 142% of control weight for t. infestans with 8 h exposure to nam. the mean weight increa ... | 1998 | 9513943 |
| ouabain-insensitive na(+)-atpase activity of malpighian tubules from rhodnius prolixus. | in the present paper, we show the existence of a furosemide-sensitive na(+)-stimulated, mg(2+)-dependent atpase activity in cell lysates of malpighian tubular cells from rhodnius prolixus, which could be the biochemical expression of the na(+)-pump. the main characteristics of this activity are: (1) k0.5 for na+ = 1.49 +/- 0.18 mm, (2) vmax = 2.8 +/- 0.1 nmol inorganic orthophosphate (pi).mg prot-1.min-1, (3) it is fully abolished by 2 mm furosemide, (4)it is insensitive to ouabain concentration ... | 1998 | 9787771 |
| characterization and cdna cloning of a hemoprotein in the salivary glands of the blood-sucking insect, rhodnius prolixus. | three major red hemoproteins, named rpsg i, ii (identical with prolixin-s) and iii, in the salivary glands of the blood-sucking insect, rhonius prolixus, show homology in n-terminal amino acid (aa) sequences, and are immunologically related. we focussed on one of these proteins, rpsg-i, in this paper. rpsg-i in fresh salivary gland extract was separated into two components (ia and ib) by isoelectric focussing gel electrophoresis. absorption spectra of rpsg-ia and ib showed soret peaks at 400 nm ... | 1998 | 9654741 |
| the origin of rhodnius prolixus in central america. | 1998 | 9580149 | |
| crystal structures of a nitric oxide transport protein from a blood-sucking insect. | the nitrophorins are heme-based proteins from the salivary glands of the blood-sucking insect rhodnius prolixus that deliver nitric oxide gas (no) to the victim while feeding, resulting in vasodilation and inhibition of platelet aggregation. the nitrophorins also bind tightly to histamine, which is released by the host to induce wound healing. here we present three crystal structures of nitrophorin 1 (np1): bound to cyanide, which binds in a manner similar to no (2.3 a resolution); bound to hist ... | 1998 | 9546222 |
| differences of susceptibility of five triatomine species to pyrethroid insecticides - implications for chagas disease vector control. | as pyrethroids are presently the favored group of insecticides to control triatomines, we performed a series of bioassays to determine the intrinsic activity of some of the main compounds used in the control campaigns, against five of the main species of triatomines to be controlled. comparing the insecticides it can be seen that lambdacyhalothrin is more effective than the other three pyrethroids, both considering the ld50 and 99 for all the three species with comparable results. on triatoma in ... | 1999 | 10677770 |
| susceptibility and resistance to insecticides of chagas disease vectors. | chemical control of chagas disease vectors appears to be the best practical way to reduce the incidence of the disease. ddt was initially tested in the 1950s for the campaigns of control of chagas disease vectors. its low level of effectiveness against triatomine caused the failure of these control actions. hch was then introduced in the southern cone and dieldrin in the north of latinoamerica. starting in the late 1960s anticholinesterasic organophosphorus and carbamate compounds were introduce ... | 1999 | 10668241 |
| the distribution and function of serotonin in the large milkweed bug, oncopeltus fasciatus. a comparative study with the blood-feeding bug, rhodnius prolixus. | the blood-feeding hemipteran, rhodnius prolixus, ingests a large blood meal at the end of each larval stage. to accommodate and process this meal, its cuticle undergoes plasticisation, and its gut and malpighian tubules respectively absorb and secrete a large volume of water and salts for rapid diuresis. serotonin has been found to be integral to the feeding process in this animal, along with a diuretic peptide(s). the large milkweed bug, oncopeltus fasciatus, tends to feed in a more continuous ... | 1999 | 12770278 |
| biochemical characterization of a thrombin inhibitor from the bloodsucking bug dipetalogaster maximus. | from the bloodsucking bug dipetalogaster maximus, a protein with anticoagulant activity was isolated and biochemically characterized. the isolated protein, named dipetalogastin, possesses an average molecular mass of 11.8 kd. its n-terminal sequence shows homology to rhodniin, a thrombin inhibitor isolated from the bug rhodnius prolixus. the in vitro anticoagulant activity of dipetalogastin occurs via the inhibition of thrombin. the anticoagulant and thrombin inhibitory potency of dipetalogastin ... | 1999 | 10702701 |
| a new factor xa inhibitor (lefaxin) from the haementeria depressa leech. | the salivary complex of the leech haementeria depressa produces potent anticoagulant components. among them, a protein named lefaxin inhibits factor xa (fxa). lefaxin was purified to homogeneity from dissected salivary complexes by gel filtration in sephadex g-150 followed by two ion exchange chromatography steps in mono-q. inhibition of fxa by lefaxin was demonstrated by the inhibition of its amidolytic activity, measured with chromogenic substrate s-2765 (apparent k(i) of 4 nm), and of its abi ... | 1999 | 10595640 |
| functional binding of a vertebrate hormone, l-3,5,3'-triiodothyronine (t3), on insect follicle cell membranes. | a vertebrate hormone, l-3,5,3'-triiodothyronine (t3), induces volume reduction in the follicle cells of locusta migratoria and rhodnius prolixus. the effect of t3 on locust follicle cells is inhibited by ouabain and by antibodies raised against a membrane binding protein for juvenile hormone (jh). [125i]-t3 binds to membrane preparations of vitellogenic follicles in a specific and saturable fashion, with a kd in the low nanomolar range. t3 and jh iii exhibited equivalent abilities to compete for ... | 1999 | 10528413 |
| extracellular glutathione peroxidase from the blood-sucking bug, rhodnius prolixus | glutathione peroxidase (gpx) activity was measured in several tissues of the blood-sucking bug, rhodnius prolixus. in contrast to the pattern found in vertebrates, where gpx is predominantly intracellular, the highest levels of this enzyme in rhodnius were found in the hemolymph. the hemolymph glutathione-dependent peroxidase accepted both h(2)o(2) and t-butyl hydroperoxide as substrates. this fact, together with the absolute glutathione dependence, inhibition by mercaptosuccinate, insensitivity ... | 1999 | 10421891 |
| daily rhythm of responsiveness to prothoracicotropic hormone in prothoracic glands of rhodnius prolixus | the synthesis of ecdysteroids by the prothoracic glands (pgs) of rhodnius prolixus occurs with a circadian rhythm throughout most of larval-adult development. this rhythm is generated by a circadian oscillator within the pgs. the principle regulator of the pgs is the cerebral neuropeptide prothoracicotropic hormone (ptth), which is also known to be released with a circadian rhythm, but it has not been shown that these daily releases of ptth are detected by the pgs. the present report examines th ... | 1999 | 10398334 |
| the distribution of a crf-like diuretic peptide in the blood-feeding bug rhodnius prolixus. | the blood-feeding bug rhodnius prolixus ingests a large blood meal, and this is followed by a rapid diuresis to eliminate excess water and salt. previous studies have demonstrated that serotonin and an unidentified peptide act as diuretic factors. in other insects, members of the corticotropin-releasing factor (crf)-related peptide family have been shown to play a role in post-feeding diuresis. using fluorescence immunohistochemistry and immunogold labelling with antibodies to the locusta crf-li ... | 1999 | 10393817 |
| kinetic analysis on nitric oxide binding of recombinant prolixin-s, a nitric oxide transport protein from the bloodsucking bug, rhodnius prolixus. | kinetics of the no binding and removal reaction of recombinant prolixin-s (rprolixin-s) were analyzed using stopped-flow spectrophotometry. the reaction was observed as a biphasic process. the rate constant of the fast phase increased linearly as no concentration increased. the rate constant at the slow phase increased as no concentrations increased at low no concentration, then reached a plateau at high no concentration. these no dependencies of the reaction are characteristic of a bimolecular ... | 1999 | 10350624 |
| protein phosphorylation during rhodnius prolixus embryogenesis: protein kinase casein kinase ii activity. | protein kinase casein kinase ii (ck ii) activity was assayed during rhodnius prolixus embryogenesis. vitellin (vt) is the main endogenous substrate during the whole development. it is maximally phosphorylated at the third day of embryogenesis by ck ii and then its phosphorylation decreases to a basal level by the time of first instar eclosion. when dephosphorylated casein was used as an exogenous substrate a different profile of enzyme activity was obtained. ck ii activity increases on day 1 aft ... | 1999 | 10319435 |
| urate synthesis in the blood-sucking insect rhodnius prolixus. stimulation by hemin is mediated by protein kinase c. | hemin is a catalyst of the formation of reactive oxygen species. we proposed that hematophagous insects are exposed to intense oxidative stress because of hemoglobin hydrolysis in their midgut (petretsky, m. d., ribeiro, j. m. c., atella, g. c., masuda, h., and oliveira, p. l. (1995) j. biol. chem. 270, 10893-10896). we have shown that hemin stimulates urate synthesis in the blood-sucking insect rhodnius prolixus (graça-souza, a. v., petretsky, j. h., demasi, m., bechara, e. j. h., and oliveira, ... | 1999 | 10092654 |
| yeast culture volatiles as attractants for rhodnius prolixus: electroantennogram responses and captures in yeast-baited traps. | responses to air currents carrying volatiles from yeast cultures were measured by means of electroantennograms (eags) in the haematophagous bug rhodnius prolixus and we tested yeast-baited traps in the laboratory. the volatiles liberated by yeast cultures generated a clear electrophysiological response, much higher than that obtained during stimulation with clean air. the addition of yeast cultures to the traps dramatically increased overnight capture. a modification performed on the traps was e ... | 1999 | 9924967 |
| neolignans inhibit trypanosoma cruzi infection of its triatomine insect vector, rhodnius prolixus. | two neolignans, burchellin and nordihydroguaiaretic acid (ndga), were toxic only to trypanosoma cruzi clone dm28c maintained in brain heart infusion (bhi) medium at a concentration of 100 microg/ml, not 10 microg/ml. when rhodnius prolixus was fed with epimastigotes of t. cruzi and treated simultaneously with a single dose of burchellin or ndga at 10 pg/ml of blood meal the number of parasites in the gut decreased. whereas burchellin was only partially active, ndga drastically reduced the number ... | 1999 | 9951960 |
| studies on a haemolymph lectin isolated from rhodnius prolixus and its interaction with trypanosoma rangeli. | we demonstrated that in rhodnius prolixus haemocyte monolayers, both trypanosoma cruzi and trypanosoma rangeli are capable of inducing haemocyte/parasite clump formation. we also purified, by one-step affinity chromatography, a haemolymph galactoside-binding lectin from r. prolixus which we believe could play an important role in the development of t. rangeli in the haemocoel of the insect vector. this lectin markedly enhanced the activation of clump formation by t. rangeli in r. prolixus haemoc ... | 1999 | 10092472 |
| invertebrate compounds acting on the hemostatic mechanism. | physiological secretions from some invertebrates have toxic effects on mammalian blood coagulation and fibrinolytic systems. some of these effects occur because the substances contained in the secretions resemble the components of the hemostatic system. some of the substances have been characterized, and have been found to have similar molecular weights or sequences, which may indicate a common ancestry. the components can be divided into five groups: antithrombic agents (group i); inhibitors an ... | 1999 | 10192653 |
| species specific detection of trypanosoma cruzi and trypanosoma rangeli in vector and mammalian hosts by polymerase chain reaction amplification of kinetoplast minicircle dna. | several groups have recently developed molecular tests for the detection of trypanosoma cruzi, the causative agent of chagas' disease. polymerase chain reaction (pcr) amplification of kinetoplast minicircle dna sequences appears to be the most sensitive method. however, the specificity of pcr-based diagnostic methods was challenged when the complete sequence of trypanosoma rangeli dna minicircles was discovered. in the present study, we conducted. pcr experiments using the s35/s36 primers in rho ... | 1999 | 10206119 |
| rhodnius prolixus infected with trypanosoma rangeli: in vivo and in vitro experiments. | studies were carried out on the activation of the prophenoloxidase (propo) in adults of rhodnius prolixus infected by short and long epimastigote forms of trypanosoma rangeli. the in vitro activation of the propo cascade using l-dopa as substrate was very low in the absence of fat body extract, hemolymph, and parasites. on the other hand, a higher po activity was observed when short, but not long, epimastigotes of t. rangeli were incubated with fresh hemolymph, fat body extract, and l-dopa. supe ... | 1999 | 10222183 |
| bednet impregnation for chagas disease control: a new perspective. | to determine the efficacy and acceptability of deltamethrin-impregnated bednets in controlling chagas disease in south america. | 1999 | 10223214 |
| modulation of murine lymphocyte responsiveness by the saliva of rhodnius prolixus (hemiptera: reduviidae). | incorporation of 3h-thymidine by splenic lymphocytes was studied in cba mice that were bitten by the triatomine bug rhodnius prolixus (stål) 14, 7, 4, and 2 d before lymphocyte isolation, respectively. in bitten mice, both spontaneous and mitogen-induced proliferative responses were reduced. the most pronounced effect was observed 4 d after exposure when lymphocytes were significantly suppressed in proliferative response to the mitogens concanavalin a, phytohemagglutinin, and bacterial lipopolys ... | 1999 | 10337105 |
| utility of the polymerase chain reaction in detection of trypanosoma cruzi in guatemalan chagas' disease vectors. | for effective control programs, accurate assessment of trypanosoma cruzi infection in vectors is essential and has traditionally been performed by microscopic examination. for particular vectors and not others, polymerase chain reaction (pcr) analysis of fecal samples recently has been shown to be an effective means of detection. the sensitivities of the pcr and microscopy for detection of t. cruzi in different anatomic sites were compared in the two major vectors of guatemala, triatoma dimidiat ... | 1999 | 10344645 |
| development of rhodnius prolixus (hemiptera: reduviidae) under constant and cyclic conditions of temperature and humidity. | development of rhodnius prolixus after eclosion until the adult stage was studied at constant temperatures (t), 15, 20, 25, 28, 35 c, and relative humidities (rh), 75, 86 and 97%, and fluctuating (16/8 hr) temperatures, t i/ii, 15/28 c, 20/25 c, 25/28 c and 25/35 c, and relative humidities, rh i/ii, 86/75% and 97/75%. eclosion or molting were not observed at 15 c and 86 or 97% rh, respectively. at 35 c and 75% rh only few insects molted. by alternating t i/ii, 15/28 c and 25/35 c, insects develo ... | 1999 | 10348991 |
| influence of brain and azadirachtin on trypanosoma cruzi development in the vector, rhodnius prolixus. | studies on the effects of decapitation, head transplantation, azadirachtin, and ecdysone therapy on the ultrastructural organization of the midgut of rhodnius prolixus, a vector of the protozoan trypanosoma cruzi, show a distinct effect on the organization of the epithelial cells. when insects are decapitated or treated with azadirachtin, the ultrastructural organiza tion of these compartments changed significantly and drastically blocked the development of t. cruzi infection. in converse experi ... | 1999 | 10366535 |
| a missing metabolic pathway in the cattle tick boophilus microplus. | heme proteins are involved in a wide variety of biological reactions, including respiration, oxygen transport and oxygen metabolism [1]. the heme prosthetic group is synthesized in almost all living organisms except for a few pathogenic bacteria and trypanosomatids that use blood as food [2] [3]. there is a general belief that all nucleated animal cells synthesize heme [1] [4]. however, blood-feeding arthropods ingest enormous amounts of vertebrate blood in a single meal and the heme pathway has ... | 1999 | 10395540 |
| mitochondrial dna sequence variation among triatomine vectors of chagas' disease. | kissing bugs or triatomines (reduviidae: triatominae) are vectors of the chagas' disease agent trypanosoma cruzi. there is a current need for more sensitive tools for use in discrimination of different bug populations and species, thus allowing a better understanding of these insects as it relates to disease transmission and control. in a preliminary analysis of the mitochondrial large subunit ribosomal rna (mtlsurrna) and cytochrome b (mtcytb) genes, we used dna sequencing to study species iden ... | 1999 | 10466963 |
| expression of a functional antibody fragment in the gut of rhodnius prolixus via transgenic bacterial symbiont rhodococcus rhodnii. | expression within insects of foreign antiparasitic gene products via microbial symbionts could be used to prevent transmission of vector-borne pathogens to vertebrate hosts. genetically transformed symbiotic bacteria rhodococcus rhodnii expressed functional antibody fragments (rdb3 encoding murine v(h)/k which binds progesterone) that were exported into the gut lumen of the triatomine bug rhodnius prolixus (hemiptera: reduviidae), a vector of chagas disease. transgenic symbionts were maintained ... | 1999 | 10484156 |
| effects of recombinant nitrophorin-2 nitric oxide complex on vascular smooth muscle. | nitrophorin-2, isolated from the salivary gland of the blood-sucking insect rhodnius prolixus, is a nitric oxide (no) binding protein. we investigated the effects of recombinant nitrophorin-2 no complex on vascular smooth muscle. the course of relaxation was relative to released no from recombinant nitrophorin-2 no complex. our data suggested nitrophorin-2 was tightly adhesive to the membranes to transport no into the cell during the insect sting. | 1999 | 10501007 |
| dipetalogastin, a potent thrombin inhibitor from the blood-sucking insect. dipetalogaster maximus cdna cloning, expression and characterization. | a cdna coding for the thrombin inhibitor dipetalogastin has been isolated from a stomach library of dipetalogaster maximus, a blood-sucking insect. the open reading frame of the cloned inhibitor cdna codes for a protein of 344 amino-acid residues. sequence analysis reveals the existence of three repeated homologous main regions, indicating that the inhibitor consists of three domains. each domain shows a double-headed structure with an internal sequence homology like rhodniin, the thrombin inhib ... | 1999 | 10561601 |
| metalloproteases in trypanosoma rangeli-infected rhodnius prolixus. | protease activities in the haemolymph and fat body in a bloodsucking insect, rhodnius prolixus, infected with trypanosoma rangeli, were investigated. after sds-polyacrylamide gel electrophoresis containing gelatin as substrate, analysis of zymograms performed on samples of different tissues of controls and insects inoculated or orally infected with short or long epimastigotes of t. rangeli, demonstrated distinct patterns of protease activities: (i) proteases were detected in the haemolymph of in ... | 1999 | 10585653 |
| [towards the elimination of the transmission of trypanosoma cruzi in honduras and central american countries]. | central america is composed of seven countries: belice, costa rica, el salvador, guatemala, honduras, nicaragua and panama. chagas disease exists in all seven countries, but with major prevalence in el salvador, guatemala, honduras and nicaragua. the main species of triatomine vectors are: rhodnius prolixus, triatoma dimidiata y rhodnius pallescens. in 1997 the central american countries launched an initiative for the vectorial and transfusion transmission control of chagas disease. the objectiv ... | 1999 | 10668252 |
| biological factors involving trypanosoma cruzi life cycle in the invertebrate vector, rhodnius prolixus. | 1999 | 10677719 | |
| immunity in rhodnius prolixus: trypanosomatid-vector interactions. | 1999 | 10677721 | |
| dependence of the entomopathogenic fungus, beauveria bassiana, on high humidity for infection of rhodnius prolixus. | the impact of relative humidity (rh) on the infective potential of the isolate bb inra 297 of beauveria bassiana (bals.) vuillemin (deuteromycotina: hyphomycetes) against first instar nymphs of rhodnius prolixus stål. (hemiptera: reduviidae) was determined. fungus-treated insects were exposed to rhs ranged from 75 to 100% at 25 degrees c. results clearly showed a threshold of humidity at ca. 96% for high and rapid mortality. after initial exposure to increasing periods of 97% (4, 8, 16, 24, 36 a ... | 1999 | 10721518 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| the crystal structure of nitrophorin 2. a trifunctional antihemostatic protein from the saliva of rhodnius prolixus. | nitrophorin 2 (np2) (also known as prolixin-s) is a salivary protein that transports nitric oxide, binds histamine, and acts as an anticoagulant during blood feeding by the insect rhodnius prolixus. the 2.0-a crystal structure of np2 reveals an eight-stranded antiparallel beta-barrel containing a ferric heme coordinated through his(57), similar to the structures of np1 and np4. all four rhodnius nitrophorins transport no and sequester histamine through heme binding, but only np2 acts as an antic ... | 2000 | 10884386 |
| synthesis of vitellogenin by the follicle cells of rhodnius prolixus. | the synthesis and secretion of vitellogenin by the ovary of rhodnius prolixus was investigated. using whole ovary or epithelial cells isolated from follicles of different sizes, it is shown that the follicle cells are a site of synthesis for this protein in the ovary. the ovaries or follicle cells were incubated in vitro with [(35)s]-methionine or (32)pi and the secretion of newly synthesized ovarian vitellogenin (o-vg) was estimated by the radioactivity associated with the immunoprecipitate or ... | 2000 | 10844247 |
| the insect salivary protein, prolixin-s, inhibits factor ixa generation and xase complex formation in the blood coagulation pathway. | prolixin-s is a salivary anticoagulant of the blood-sucking insect, rhodnius prolixus, and known as an inhibitor of the intrinsic xase. we report here its inhibitory mechanisms with additional important anticoagulation activities. we found prolixin-s specifically bound to factor ix/ixa in the presence of ca(2+) ions. light scattering and surface plasmon resonance studies showed that prolixin-s interfered with factor ix/ixa binding to the phospholipid membrane, indicating that prolixin-s inhibit ... | 2000 | 10692472 |
| fatty acid incorporation by rhodnius prolixus midgut. | [(14)c]oleic acid injected into the hemocoel of rhodnius prolixus females was shown to rapidly associate with lipophorin particles. half of the lipophorin-associated [(14)c]oleic acid was transferred in about 5 min to different organs, but the midgut was the main organ to take it up on day 10 after a blood meal. the rate of [(14)c]oleic acid incorporation by the midgut was high up to 15 min after injection and then declined. the [(14)c]oleic acid incorporated by the midgut was found in phospholi ... | 2000 | 10685097 |
| adenosine modulates the (na(+)+k(+))atpase activity in malpighian tubules isolated from rhodnius prolixus. | the role of adenosine on regulation of the (na(+)+k(+))atpase activity present in the malpighian tubules isolated from rhodnius prolixus was investigated. adenosine decreases the (na(+)+k(+)) atpase specific activity by 88%, in a dose-dependent manner, with maximal effect at a concentration of 10(-9) m. this effect was mimicked by n(6)-cyclohexyladenosine (cha) at 10(-8) m, an agonist for a(1) adenosine receptor, and was reversed by 10(-9) m 8-cyclopentyl-1,3-dipropylxanthine (dpcpx), an antagon ... | 2000 | 10644971 |
| [current situation with chagas disease vector control in the americas]. | this article identifies and describes various epidemiological aspects in the natural transmission of chagas disease in the americas. it also examines the relative importance of the principal vector species in the disease's transmission and the control levels that are feasible in each instance. estimations of the population at risk, number of infected cases, and number of chronic cases are presented. prospects for control are discussed on the basis of past results to predict the expected results ... | 2000 | 11119318 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |