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[rhodnius prolixus stal, 1859, in goiás, brazil. preliminary report]. 19826764950
the effect of lampit on trypanosoma rangeli in experimentally infected mice.mice experimentally inoculated with metacyclic forms of trypanosoma rangeli were given orally 10, 25, 50 or 100 mg/kg of body weight/day of lampit on 20 consecutive days. the results of combined examinations of fresh blood, giemsa stained blood preparations, blood cultures, blood concentration, repeated xenodiagnosis with rhodnius prolixus and blind passages via triatomine bites to other mice demonstrated that a dose of 50 to 100 mg/kg/day of the drug eliminated t. rangeli from the blood of all ...19826814024
the activity of nifluridide on reduviids and rodent and human trypanosomes.the ability of nifluridide to kill reduviids was assayed in mice fed 7 ppm in diet and on cattle injected subcutaneously at 5 mg/kg body weight. nifluridide was systemically active against triatoma infestans on mice and rhodnius prolixus on cattle. no effects on trypanosoma (schizotrypanum) cruzi could be detected in the intestinal contents of triatoma infestans killed by the compound. in vitro and in vivo studies were conducted to determine the effects of nifluridide on trypanosomes growing in ...19826815915
developmental stages of trypanosoma cruzi-like flagellates in cavernicola pilosa.the developmental stages of trypanosoma cruzi ssp., found in the intestinal tract of cavernicola pilosa, are described and measurements given for nine life stages. the frequencies of the various stages in foregut, midgut and hindgut of the triatomines are provided; parasites were rare in the foregut and metatrypomastigotes were seen only in the mid- and hindguts. all adult bugs examined harboured intestinal infections of t. cruzi-like flagellates, large clumps of amastigotes were frequently obse ...19826820697
the effects of precocene ii on reproduction and development of triatomine bugs (reduviidae: triatominae).precocene ii is a botanically derived chemical that inhibits the production of juvenile hormone (jh) in insects. the effects of this anti-jh compound on molting and growth by rhodnius prolixus and triatoma dimidiata and reproduction in r. prolixus were tested and the efficacy of precocene ii as a fumigant was assessed. precocene ii induced precocious metamorphosis in both species when applied by either contact exposure or fumigation, and this effect could be prevented by juvenile hormone replace ...19827041667
ovarian motility in mated rhodnius prolixus requires an intact cerebral neurosecretory system. 19827129081
diphosphoglycerate and phytic acid as feeding stimulants for the blood-feeding bug rhodnius prolixus.1. the compounds 2,3-diphosphoglycerate (dpg), phytic acid (pa) and adenosine triphosphate (atp) were tested as gorging stimulants for rhodnius prolixus. all three are potent phagostimulants, with ed50 values less than 10 microm; in contrast, only atp stimulates the black fly simulium venustum, with an ed50 of 13 microm. 2. equimolar mixtures of dpg and atp showed pronounced synergism, causing 75% of test r. prolixus to gorge at a dose of 0.3 microm. 3. the response to dpg and pa supports the hy ...19826124351
diphosphoglycerate rather than atp as a physiological phagostimulant factor for rhodnius prolixus. 19836339262
factors controlling the volume of feces produced by triatomine vectors of chagas' disease.triatomine species influenced volume of feces produced; triatoma dimidiata produced the largest volume of feces followed by panstrongylus megistus, rhodnius prolixus, and triatoma infestans. moreover, stage and sex affected fecal production; 5th-stage female nymphs excreted the largest volume of feces. the amount of blood ingested was significantly correlated with the volume of feces produced in 10 out of 11 experimental groups. triatome size and volume of feces produced were less closely correl ...19836142633
studies on trypanosoma rangeli tejera, 1920. vi. developmental pattern in the haemolymph of rhodnius prolixus.the morphological sequence of trypanosoma rangeli development in the body cavity of rhodnius prolixus is described. the metacyclic trypanosome is the product of successive division and transformation during the intra and extracellular development in the haemocoele. the significance of the early invasion of t. rangeli into the haemolymph is discussed. the epidemiological importance of the developmental pattern of t. rangeli in the vectors haemolymph and the host-response to the parasite are consi ...19836400168
susceptibility of insect-borne, metacyclic forms of trypanosoma cruzi to antibody-mediated mechanisms of destruction.the effect of passive antibody transfer against infection with vector-borne, metacylic forms of trypanosoma cruzi, and possible mechanisms of immunologic lysis of these organisms, were examined in this work. anti-t. cruzi antibodies from mice surviving an infection conferred marked protection against challenge with a lethal dose (2,000 organisms) of metacyclic flagellates isolated from the reduviid insect rhodnius prolixus. in vitro lysis of these parasites by immune sera from mice or chronic ch ...19836418013
diuresis from stimulation of left atrial receptors in dogs: further purification of the causative agent from plasma.stimulation of atrial receptors by distension of a balloon in the left atrium of anaesthetized dogs results in a reflex diuresis mediated by an unknown humoral agent. this paper reports the further purification from plasma of acetone extracts of the humoral agent which may mediate the diuretic response. activity of the humoral agent was detected using the malpighian tubules of rhodnius prolixus. gel filtration of the acetone extracts on sephadex g-25 and g-100, followed by dialysis of the fracti ...19836856747
abolition of atrial receptor diuresis and of release of humoral agent by cooling the vagal nerves.stimulation of atrial receptors in anaesthetized dogs results in a reflex increase in urine flow mediated by vagal myelinated fibres and, in part, by a humoral agent of unknown identity. the humoral agent has been detected by an in vitro preparation of the malpighian tubules of rhodnius prolixus. the purpose of this investigation was to determine whether the present extract of plasma purporting to contain the humoral agent is also related to the reflex diuresis. in nine chloralose anaesthetized ...19836856748
cross-reactivity of vector-borne metacyclic forms of trypanosoma cruzi with mammalian and culture stages.metacyclic forms of trypanosoma cruzi isolated from the hindgut of infected insect vectors (rhodnius prolixus) were found to be immunologically cross-reactive with cultured epimastigote, amastigote, and metacyclic stages of the parasite as well as with bloodstream trypomastigote forms by direct agglutination and indirect immunofluorescence techniques. sera specific for each of these forms of the parasite systematically yielded maximal antibody titers when measured against the homologous antigen, ...19836195335
functional design of microvilli in the malpighian tubules of the insect rhodnius prolixus.the malpighian tubules of rhodnius prolixus are divided into two regions; the upper tubule, which is the site of isosmotic secretion and haemolymph filtration, and the lower tubule where water and kcl are resorbed. in the upper tubule the microvilli are arranged in clumps consisting of several hundred microvilli lying closely parallel. the microvillar plasma membranes do not touch but are held approximately equal to 16 nm apart along the full length of the microvilli. as a consequence, the extra ...19836348047
crystallized hemoglobin in rhodnius prolixus after a blood meal on guinea-pig.several blood-sucking arthropods, after a blood meal, are able to store the hemoglobin from their hosts in a crystalline state in their digestive system. guinea-pig hemoglobin crystallizes in the stomach of the reduviid bug rhodnius prolixus in two different crystal types. we show them to be crystallographically identical and to contain the same liganded state of hemoglobin, i.e. they represent different habits of the same crystal modification. the hemoglobin crystallizes in oxy-form and ages in ...19836360705
studies on trypanosomes in the taiwan monkey.fifty-three or 9% of 594 taiwan monkeys, macaca cyclopis, were found infected with a trypanosome species. the parasites were recovered from monkey blood in diaphasic blood-agar culture medium with a locke's solution overlay. trypanosomes were found on only a few thick blood smears and no dividing or multiplying forms were found. some of the organisms had a free-flagellum (4.7 microns), an undulating membrane and both ends of the body were pointed. the total length averaged 41.7 microns; nucleus ...19836673131
morphology of the dorsal vessel in the abdomen of the blood-feeding insect rhodnius prolixus.the dorsal vessel (dv) in the abdomen of the blood-feeding insect rhodnius prolixus was divided functionally into two regions, the heart, into which haemolymph entered the dv through four pairs of ostia located in abdominal segment vii, and the aorta, along which the haemolymph was propelled from abdominal segment vi to the thorax. osmium-fixed whole mounts revealed the dv to consist of spirally arranged striated muscle fibers and to possess two rows of ventrally attached longitudinal fibers ext ...19832187100
removal of insect basal laminae using elastase.we have used the enzyme elastase to remove the basal lamina of epithelia from two insects: the upper malpighian tubules of rhodnius prolixus and imaginal discs of drosophila melanogaster. removal of the basal lamina was confirmed using scanning and transmission electron microscopy. use of the technique on the malphighian tubules of rhodnius reveals for the first time the three-dimensional organization of the circumferential folds of the basal plasma membrane. elastase is much more effective in r ...19846431633
secretion by the malpighian tubules of rhodnius prolixus stal: electrical events.transepithelial and intracellular potentials have been simultaneously recorded from rhodnius upper malpighian tubules before and after stimulation of fluid secretion. the transepithelial electrical response to the diuretic hormone mimic 5-hydroxytryptamine (5-ht) was triphasic; recordings of intracellular potential changes indicated that the three phases represented successive events at the apical membrane. depolarizations produced by increasing the bathing medium potassium concentration indicat ...19846379094
effects of juvenile hormone analogue on ecdysis prevention induced by precocene in rhodnius prolixus (hemiptera:reduviidae).precocene ii, added to the meal of fourth-instar larvae of rhodnius prolixus (25 micrograms/ml of blood), induced an increase in the duration of the molting cycle. this effect was related to the decrease of both the nuclear area of the prothoracic gland cells and the mitotic activity in epidermal cells. juvenile hormone analogue applied topically (60 micrograms/insect) together with precocene ii treatment avoided atrophy of the prothoracic glands and induced a higher number of epidermal mitosis ...19846398393
studies on trypanosoma rangeli tejera, 1920. vii--its effect on the survival of infected triatomine bugs.the pathological effects of trypanosoma rangeli on rhodnius prolixus and r. robustus, and the relation of mortality to infection, were studied under laboratory conditions. frequent observations revealed that when the first instar nymphs of r. prolixus and r. robustus were infected with t. rangeli, survival of the bugs during the stages of development to the adult stage decreased. this decrease was statistically significant when compared with uninfected control-bugs, indicating that t. rangeli is ...19846399091
passage of solutes through walls of malpighian tubules of rhodnius by paracellular and transcellular routes.the walls of isolated upper malpighian tubules of the insect, rhodnius prolixus, are much more permeable to small relatively unchanged solutes (ethanol, xylose, and mannitol) than to larger or more charged solutes (acetate, glycine, tyrosine, and inulin). the more permeable solutes rapidly reach concentrations in the tubule cells equivalent to their concentrations in the bathing medium; the less permeable solutes do not penetrate into the cells. the time course of accumulation of permeable solut ...19846426328
epidemiology of trypanosoma cruzi in the oriental plains of colombia.epidemiologic studies to define the domiciliary and extradomiciliary transmission cycles of trypanosoma cruzi and trypanosoma rangeli in the oriental plains of colombia were conducted in the gallery forests near carimagua and el porvenir. one-hundred and seven palm trees belonging to nine genera were examined; triatomines were found in only three palm species, the leaves of which are locally used for roof thatching: 2/29 maximiliana elegans, 1/7 mauritia flexuosa and 7/7 scheelea sp. bugs were a ...19846439062
[finding of rhodnius prolixus stal, 1859, in babassu palm trees]. 19846443714
dissociation of insect malpighian tubules into single, viable cells.the malpighian tubules of insects are generally composed of more than one cell type. in the hemipteran rhodnius prolixus, the tubules are divided into two regions, termed the upper and lower tubules, each of which is composed of a distinct cell type. in the dipteran aedes taeniorhynchus, primary and stellate cells are interspersed throughout the length of the tubules. we report here techniques for the dissociation of the malpighian tubules of both of these species into single cells. tubules are ...19846533146
serotonin modulation of the release of sequestered [3h]serotonin from nerve terminals in an insect neurohemal organ in vitro.exogenous tritiated serotonin ([3h]5-ht) is taken up by and released from serotonin-containing fibers within abdominal nerves of rhodnius prolixus during in vitro incubations. sequestered [3h]5-ht behaves as expected of an endogenous neurosecretory product in this system. release is ca2+-dependent during both k+-induced and physiologically induced secretory episodes. the kinetics of the release of sequestered label parallels the kinetics of release of endogenous neurohormones. preloaded preparat ...19846380644
cytological evidence for serotonin-containing fibers in an abdominal neurohemal organ in a hemipteran.the abdominal neurohemal organs of the hemipteran rhodnius prolixus contain an extensive serotonin containing arborization. endogenous serotonin within fibers and terminals in the neurohemal area were detected with histochemical and immunocytological techniques. the abdominal nerves which contain the neurohemal organs selectively sequester exogenous serotonin. serotonin and its metabolites are biochemically detected within the mesothoracic ganglion, which is a known source of projections into th ...19846380643
cytophysiological correlations between prothoracic gland activity and hemolymph ecdysteroid concentrations in rhodnius prolixus during the fifth larval instar: further studies in normal and decapitated larvae.hemolymph ecdysteroid titers in fifth instar larvae of rhodnius prolixus were determined by radioimmunoassay, and their prothoracic glands were excised and examined by electron microscopy. during the last larval instar, the titer of ecdysteroid increased between the head-critical period until day 13, at which time the peak titer was 3100 pg 20-hydroxyecdysone equivalents/microliter. the activation of secretory cells at the time of the second period of prothoracicotropic hormone release was corre ...19846370785
circadian control of a daily rhythm in hemolymph ecdysteroid titer in the insect rhodnius prolixus (hemiptera).the hemolymph levels of the insect molting hormone (ecdysteroid) during the week preceding ecdysis in fifth-instar male rhodnius prolixus have been determined using a radioimmunoassay. when animals are kept on light-dark cycles, the titer displays massive daily increases and decreases producing a daily rhythm. this rhythm is maintained with a period of approximately 24 hr in continuous darkness. the free-running period of the rhythm was determined at 24 and 28 degrees and found to be temperature ...19854043725
variations during the gonotrophic cycle in the titer of the myotropic ovulation hormone and the response of the ovarian muscles in rhodnius prolixus.the response of the ovarian muscles to a standard preparation of the myotropic ovulation factor from identified neurosecretory cells in the brain of rhodnius prolixus increases after feeding in both virgin and mated females. this increase is unaffected by removal of the neurosecretory cells and by increases imposed on the resting tension of the ovaries used in the bioassay. the hemolymph titer of the myotropic activity as determined by bioassay exhibits a peak after feeding in both mated and vir ...19853891505
glial cell contacts in insects: effects of feeding on intercellular junctions.the intercellular junctions associated with the modified glial cells of the perineurium have been examined in the ganglia and main abdominal nerves of the blood-sucking bug rhodnius prolixus, both before and and after feeding, by means of freeze-fracture and tracer studies. it was found that the pleated septate junctions found in the main abdominal nerve have many fewer septa than those found in the ganglion. these junctions appear to provide the flexibility needed for the movement of cells whic ...198518620150
laboratory repellent tests against rhodnius prolixus (heteroptera: reduviidae). 19853884812
[differentiation between trypanosoma cruzi and t. rangeli in the intestine of the vector rhodnius prolixus, based on the behavior of these flagellates with regard to the lytic activity of complement]. 19853892618
isozyme profiles of trypanosoma cruzi stocks from colombia and ecuador.a total of 74 of 82 domestic rhodnius prolixus from the same locality in eastern colombia were found to be infected with trypanosoma cruzi or t. rangeli. one of three domestic triatoma dimidiata from ecuador also showed t. cruzi infection. a total of 59 t. cruzi stocks from these and five other localities in colombia were isolated from man, marsupials and triatomine bugs. cellulose-acetate electrophoresis of nine or ten enzymes characterized all t. cruzi stocks as zymodeme 1 (reference clone sil ...19853896169
parasitism of telenomus costalimai (hymenoptera: scelionidae) on rhodnius prolixus (hemiptera: reduviidae) under laboratory conditions: effects of density. 19853908680
feeding, molting, and egg production in rhodnius prolixus (hemiptera: reduviidae) fed repeatedly on the same swiss mouse hosts. 19853908681
a protein diet initiates oogenesis in rhodnius prolixus.oogenesis in r. prolixus females is induced by feeding blood, blood plasma, a suspension of washed erythrocytes, or 5% solutions of egg albumin, bovine serum albumin or hemoglobin. unfed females and those fed saline, casein hydrolysate, dextran or sucrose do not initiate oogenesis. the juvenile hormone analogue epoxygeranylgeraniol methyl ester induced oogenesis in unfed females as well as in ethoxyprecocene ii-treated insects. the results show that a protein meal was sufficient to initiate ooge ...19853913479
[natural hosts of trypanosoma cruzi in french guiana. high endemicity of zymodeme 1 in wild marsupials].during an epidemiological survey in french guiana, three species of marsupiala were found infected by trypanosoma cruzi with high infection rates (30,8% for didelphis marsupialis). six triatomine bug species were recorded, five of them being well known vectors of chagas' disease. iso-enzyme characterization of 22 stocks isolated (16 from d. marsupialis, 3 from philander opossum and 3 from rhodnius prolixus) revealed that they were all related to zymodeme 1 of miles. the silvatic cycle is endemic ...19853923891
trypanosoma (herpetosoma) rangeli tejera, 1920: mouse model for high, sustained parasitemia.the neotropical mammalian parasite trypanosoma (herpetosoma) rangeli tejera, 1920 is difficult to study due to the scarcity of blood forms in the vertebrate host. high and persistent parasitemias (up to 7 times the original inoculum at the peak, and persisting for up to 2 wk) were obtained by i.p. inoculation of infant (6.0 g) male white mice (nmri strain) with 15 x 10(3) trypomastigotes/g body weight from 12-day-old cultures of the "dog-82" strain of t. rangeli. this strain was cultured 15 mo a ...19854032147
[prolixase, a fibrinolytic enzyme isolated from rhodnius prolixus (heteroptera, reduviidae): antigenic properties].antigenic properties of prolixase are studied showing that this fibrinolytic enzyme, induces in the rabbit, the formation of precipitating but slightly, hemagglutinating homologous antibodies.19852418798
morphogenetic effects of precocene ii on the immature stages of rhodnius prolixus. 1985366817
chemical structure, juvenile hormone activity and persistence within the insect of juvenile hormone mimics for rhodnius prolixus. 1986323368
trypanosoma cruzi and trypanosoma rangeli in saimiri sciureus from bolivia and saguinus mistax from brazil.examination of blood films for trypanosomes in primates housed at the tulane university delta regional primate research center showed that 47% (32/68) of the bolivian saimiri sciureus and 51% (68/135) of brazilian saguinus mistax harbored one or more types: trypanosoma (schizotrypanum) cruzi in 6% to 7% and trypanosoma (herpetosoma) spp. or trypanosoma (megatrypanum) spp. in 39% and 45%, respectively. trypanosomes were isolated from a sample of the infected monkeys and morphobiological studies w ...19863082228
establishment of baseline data on the insecticide susceptibilities of the chagas' disease vector rhodnius prolixus in venezuela. 19863103804
[antidiuretic mechanism in rhodnius prolixus (stal, 1859) (hemiptera, reduviidae)].an antidiuretic mechanism is proposed for rhodnius prolixus, whose activity is manifested when the diuretic phase has terminated and is maintained until the insect has fed again. presumably this mechanism acts at the level of the proximal rectal sphincter and is inhibited by ingestion, mechanical distension of the gut and central disinhibition by decapitation. it is suggested that the antidiuretic activity is maintained by the nervous system and is modified when there is distention of the gut or ...19863302595
[laboratory maintenance of trypanosoma (herpetosoma) rangeli tejera, 1920].two laboratory maintenance systems of trypanosoma rangeli were compared. the maintenance by weekly subinoculations in tobie's culture medium and the intrafemoral inoculation of rhodnius prolixus with cultured flagellates, resulted in loss of infectivity of the metacyclic salivarian trypomastigotes for mice, ten months after maintenance in culture. with the system of cyclical passes through culture-rhodnius-mouse-culture-rhodnius, the infectivity of the metacyclic trypomastigotes for mice, was ma ...19863313550
rhodnius neivai: a new experimental vector of trypanosoma rangeli.rhodnius neivai was as efficient as rhodnius prolixus and rhodnius robustus in transmitting by bite a colombian strain of trypanosoma rangeli following its inoculation into the hemocoel. under conditions of the study the strain of t. rangeli had a high and constant infectivity to the salivary glands of r. prolixus, its natural vector in colombia. six species of triatoma and dipetalogaster maximus likewise inoculated did not develop metatrypomastigotes in the salivary glands. of the 12 known spec ...19863518505
excretion of trypanosoma cruzi by various stages of rhodnius prolixus. 19863528006
species-specific allergens from the salivary glands of triatominae (heteroptera:reduviidae).we investigated allergenic cross-reactivity among species of the blood-feeding insects of the subfamily triatominae. by skin testing, patients allergic to either triatoma protracta or t. rubida gave positive responses only to the respective salivary antigen. rast-inhibition experiments demonstrated that binding of ige antibodies to t. protracta antigen was not inhibited by salivary extracts from t. rubida, t. cavernicola, t. rubrofasciata, or rhodnius prolixus. the same level of species specific ...19863531291
density-dependent perception of triatomine bug bites.pots containing different densities of rhodnius prolixus were strapped on to the upper and lower arms and legs of six human volunteers. analysis of the volunteers' perception of the bugs' probing activity showed a clear linear trend of perception according to bug density. comparison with other results suggests that in humans as well as other vertebrate hosts, density dependent irritation from the bug bites and consequent disturbance and interruption of bugs' feeding could provide the mechanism b ...19863541809
the affinity of the lectins ricinus communis and glycine maxima to carbohydrates on the cell surface of various forms of trypanosoma cruzi and trypanosoma rangeli, and the application of these lectins for the identification of t. cruzi in the feces of rhodnius prolixus.flagellates of trypanosoma cruzi (stock molino 1), obtained from the intestine of experimentally infected rhodnius prolixus, grown in cellular or acellular culture, as well as from the blood of infected mice, were examined by a direct fluorescence test using the lectins rca (ricinus communis-120) and sba (soy bean agglutinin; glycine maxima), conjugated with fluorescein isothiocyanate, for the detection of beta-d-galactose and alpha,beta-n-acetyl-d-galactosamine on the membranes of the flagellat ...19862877548
the surface morphology of the midgut cells of rhodnius prolixus stål (hemiptera: reduviidae) during blood digestion.the surface morphology of the midgut cells of rhodnius prolixus is examined using scanning electron microscopy. before feeding, the microvilli are devoid of any extracellular structures and can be observed in both fracture faces and surface views. by 3 days after feeding, patches of extracellular membrane layers are observed on the surface of the midgut cells and by 7 days the extracellular membrane layers form an incomplete sheet overlying the microvilli, such that the microvilli are no longer ...19862882663
induction of rhythmic modulation of haemolymph ecdysteroids in the insect rhodnius prolixus by treatments which elicit rhythmic ecdysis.the titer of moulting hormones (ecdysteroids) in fifth instar male rhodnius displays a gradual decline throughout the week preceding ecdysis when animals are maintained in constant light (ll). multiple sampling of haemolymph from the same animal reveals a constant rate of decline with no increases in titer observed. however, 20-hydroxyecdysone (20he) provokes increases in the titer of ecdysteroids which occur between 18 and 27 hr after injection. multiple injections of 20he provoke regular chang ...19863557060
salivary apyrase of rhodnius prolixus. kinetics and purification.the salivary apyrase activity of the blood-sucking bug rhodnius prolixus was found to reside in a true apyrase (atp diphosphohydrolase, ec 3.6.1.5) enzyme. the crude saliva was devoid of 5'-nucleotidase, inorganic pyrophosphatase, phosphatase and adenylate kinase activities. atp hydrolysis proceeded directly to amp and pi without significant accumulation of adp. km values for atp and adp hydrolysis were 229 and 291 microm respectively. ki values for atp and adp inhibition of adp and atp hydrolys ...19863010945
nurse cell-oocyte interaction: a new f-actin mesh associated with the microtubule-rich core of an insect ovariole.fluorescent staining of rhodnius prolixus ovarioles with rhodaminylphalloidin revealed an elaborate interconnecting meshwork of f-actin encasing the microtubule rich core. the thick actin struts have branches extending partially into the nurse cell lobes extending from the syncytical core. basally the network ends at the nurse cell-pre-follicular interface and does not extend into the trophic cords. light microscopy, tem and sem show the dense fibrous struts have numerous branch points creating ...198618620180
experimental analysis of rhodnius prolixus (insecta, hemiptera) embryogenesis. 19863749156
vitellin and vitellogenin characterization of triatoma infestans and related species.the vitellogenin-vitellin (vg-vn) of triatoma infestans is a glycolipoprotein with a mol. wt. of 220,000; is a high density lipoprotein (1.18-1.21 g/ml) with low electrophoretic mobility at ph 8.2. there are many common proteins present in females, males, nymphs and eggs, but none is a glycolipoprotein. the major band of protein revealed a mol. wt. of 43,000, it is an anodic protein which appears in all the fractions of saline gradient. males and females have a glycolipoprotein with electrophore ...19863111174
the roles of haemolymphatic lipoproteins in the oogenesis of rhodnius prolixus.the fates of purified 32p-vitellin and 32p-lipophorin were followed in vitellogenic females of rhodnius prolixus. while the radioactivity from 32p-vitellin 6 hours after injection was found almost exclusively in the ovary, the radioactivity from injected 32p-lipophorin was found distributed among several organs. in the ovary, the radioactivity from 32p-vitellin was associated with the contents of the yolk granules. 32p-lipophorin delivered a great amount of radioactive phospholipids to the ovary ...19873334405
effects of precocene and azadirachtin in rhodnius prolixus: some data on development and reproduction.the results presented in this paper clearly indicate that precocene and azadirachtin are effective inhibitors of moulting and reproduction in the hemipteran rhodnius prolixus. the time of application is important and only applications of these substances early in the intermoulting period cause their effects in nymphs. the inhibition of moulting is fully reversed by ecdysone therapy. precocene and azadirachtin also affected drastically the oogenesis and egg deposition in this insect. precocene-in ...19873334403
inputs to the hormonal control of egg development in rhodnius prolixus.this paper re-examines existing data on the environmental inputs governing egg production in rhodnius prolixus. feeding has a direct effect on egg production such that the product of the unfed weight of the female times the weight of the blood meal is a good predictor of the number of eggs produced. mating modifies this input, so that mated females produce more eggs. egg production is governed by the corpus allatum, and indirect evidence suggests that the number of eggs producted by a female is ...19873334399
demonstration of a proallatotoxin-sensitive period in 4th-instar nymphs of rhodnius prolixus.1. topical application of the proallatotoxin ethoxyprecocene ii (60 micrograms/nymph) to 4th-instar nymphs of rhodnius prolixus at various times before and after a blood meal induced precocious metamorphosis. 2. the highest percentage of adultoids was obtained when proallatotoxin was applied prior to feeding or up to day 3 after the blood meal. 3. the proallatotoxin-sensitive period ended 4 days after feeding just before the maximum peak of ecdysteroid concentration in the hemolymph. 4. the sign ...19873318976
a relationship between the inhibition of heparan sulfate and chondroitin sulfate synthesis and the inhibition of molting by selenate in the hemipteran rhodnius prolixus.the insect rhodnius prolixus synthesizes heparan sulfate and chondroitin sulfate after a blood meal containing [35s]-inorganic sulfate. a 40 to 80% inhibition of heparan sulfate synthesis was obtained when the meal was supplemented with 10(-5) and 10(-4) m sodium selenate respectively. likewise an inhibition of the molting in the order of 30 to 60% was observed when the insects were fed with blood containing 10(-5) and 10(-4) m selenate respectively. the insects after a subsequent meal without s ...19872956948
polymorphic organization of the endoplasmic reticulum of the malpighian tubule. evidence for a transcellular route.isosmotic fluid absorption carried out by many mammalian epithelia appears to be similar to the isosmotic secretion of insect epithelia such as the malpighian tubules, which are responsible for urine formation and osmoregulation. we have studied by electron microscopy (80 kv) the three-dimensional characteristics of organelles in the malpighian tubules of rhodnius prolixus using thick sections (0.3-0.5 microns) and uranyl and lead impregnation. the er presents a different organization in the upp ...19873079270
predation on rhodnius prolixus (hemiptera: reduviidae) by the spider theridion rufipes (araneida: theridiidae). 19873546692
lack of enzyme polymorphism in trypanosoma rangeli stocks from sylvatic and domiciliary transmission cycles in colombia.although trypanosoma rangeli is biologically and morphologically distinct from trypanosoma cruzi, these two hemoflagellates are epidemiologically linked. we report the results of enzyme electrophoretic studies of t. rangeli stocks isolated from sylvatic and domiciliary rhodnius prolixus, and infected humans inhabiting foci in which t. cruzi was sympatrically transmitted. t. rangeli stocks displayed electrophoretically detectable polymorphism for only a single enzyme, isocitrate dehydrogenase (ic ...19873812885
the permeability properties of septate junctions in malpighian tubules of rhodnius.this paper describes the structural characteristics and permeability properties of the smooth septate junctions between the upper malpighian tubule cells of a blood-sucking bug, rhodnius prolixus. the permeability of the paracellular route was tested only for solutes that could be demonstrated not to cross the epithelium via the cellular route. the intercellular clefts were readily permeated by sucrose, inulin and polyethylene glycol (peg), showing a higher permeability to molecules of smaller r ...19873320067
characterization of inducible lysozyme activity in the hemolymph of rhodnius prolixus.1. the characterization and partial purification of an induced lysozyme activity in the hemolymph of adult rhodnius prolixus inoculated with micrococcus lysodeikticus is described. 2. little or no activity against m. lysodeikticus appeared in the first hours after inoculation, but the activity increased reaching a maximum 4 days later, which was maintained to day 12. 3. the activity was characterized as lysozyme on the basis of the following considerations: 1) ph optimum and thermostability at a ...19873330677
studies on trypanosoma rangeli tejera, 1920. ix. course of infection in different stages of rhodnius prolixus.frequent individual observations od different stages of rhodnius prolixus exposed to trypanosoma rangeli, revealed a higher susceptibility to infection in the bugs exposed during the two first instars. the mortality rate in infected bugs was significantly higher than in controls, indicating that the parasite was responsible for the majority of deaths. an analysis of the mortality distribution, per instar, is presented. statistical analysis of deaths among the different infected instars, showed t ...19873333807
insect-borne and culture-derived metacyclic trypanosoma cruzi: differences in infectivity and virulence.we report in this paper significant differences in the virulence of insect-derived and cultured metacyclic forms of trypanosoma cruzi which are morphologically indistinguishable. mice infected intraperitoneally with 10(3) metacyclic t. cruzi isolated from rhodnius prolixus showed average parasitemia levels greater than 2 x 10(5) organisms/ml around day 10 post-infection (when first measured) and peak levels recorded on day 16 post-infection exceeded 4 x 10(7) organisms/ml. none of these animals ...19873107410
[method of biological control of triatominae, vectors of chagas disease, using entomopathogenic hyphomycetes. preliminary study].bioassays determined the pathogenic activity of 14 strains of 5 entomopathogenic hyphomycetous species (fungi imperfecti), beauveria bassiana, beauveria brongniartii, metarhizium anisopliae, nomuraea rileyi and paecilomyces fumosoroseus to rhodnius prolixus. treatments consisted of direct spraying with conidial titrated suspensions on first instar larvae. when tested at 3 x 10(5) conidia/cm2, only 2 strains, b. bassiana n. 297 and b. bassiana n. 326 killed 100% of larvae at 10 days post-exposure ...19873111731
density-dependent timing of defaecation by rhodnius prolixus, and its implications for the transmission of trypanosoma cruzi.transmission of trypanosoma cruzi is crucially dependent on the timing of defaecation by their insect vectors. experimental studies on rhodnius prolixus nymphs revealed a negative correlation between blood meal weight and defaecation time. bugs which fed to repletion defaecated on average 7 min after feeding, whereas bugs with interrupted feeds defaecated about 1 h later. as blood meal weight of triatomine bugs is density-dependent, these results suggest that the greatest risk of successful t. c ...19873113007
histochemical studies of uric acid in some insects. 3. excretion of uric acid by the malpighian tubules in calliphora vicina and rhodnius prolixus.in adult calliphora uric acid is excreted throughout the malpighian tubules. histochemical preparations for the light microscope show uric acid passing through the cells and forming crystalline spheres in immediate contact with the microvilli. uric acid appears to be synthesized and discharged into the haemolymph by the fat body cells. in rhodnius there is no visible uric acid in the cells or lumen of the upper segment of the tubule (two-thirds of the total length of the tubule) apart from occas ...198718620198
developmental time and mortality in larvae of the reduviid bugs triatoma infestans and rhodnius prolixus after coprophagic infection with blastocrithidia triatomae (trypanosomatidae). 19883127477
the initial stages in the action of an insecticidal delta-endotoxin of bacillus thuringiensis var. israelensis on the epithelial cells of the malpighian tubules of the insect, rhodnius prolixus.the effects of the 27 x 10(3) mr insecticidal delta-endotoxin from bacillus thuringiensis var. israelensis have been studied using, as a model system, isolated insect malpighian tubules. at all concentrations of the toxin higher than 1 microgram ml-1 (4 x 10(-8) moll-1) applied to the outer surface of the tubules, fluid secretion failed within about 30 min. except at very high concentrations, where failure always takes at least 30 s, there was an inverse relationship between the concentration of ...19883198707
morphometric analysis of rhodnius prolixus stal (hemiptera:reduviidae) midgut cells during blood digestion.post-feeding ultrastructural modifications to the midgut cells of rhodnius prolixus are quantified using morphometry. changes in relative and absolute volumes and/or surface areas are demonstrated for the whole cells, nuclei, mitochondria, rough endoplasmic reticulum, lysosomes, golgi apparatus, storage vesicles, glycogen, microvilli, and basal labyrinth, before and during blood digestion. these parameters are separately determined for cells from each of the three midgut regions, and are correla ...19883043761
[behavior of the infection and morphologic differentiation of trypanosoma cruzi and t. rangeli in the intestine of the vector rhodnius prolixus]. 19883070649
[feeding and defecation patterns in 5th instar nymphs of 4 species of triatomines (rhodnius prolixus, triatoma pallidipennis, t. infestans and t. brasiliensis, hemiptera, reduviidae)]. 19883071060
effects of precocene and azadirachtin on the development of trypanosoma cruzi in rhodnius prolixus. 19883075695
a novel receptor capable of monitoring applied pressure in the abdomen of an insect.a pair of receptors, responding tonically to pressure applied internally, occurs on the ventral body wall of abdominal segments two to five in the adult of the blood-feeding insect, rhodnius prolixus. these receptors are located in a region of the body wall subject to forces directly related to the size and movement of the stomach, an enlarged region of the midgut which stores the blood meal, and are therefore well suited for monitoring the degree of distension there. the initiation of many endo ...198817820895
sex differences in the profiles of prothoracic gland synthetic activity and of hemolymph ecdysteroid titers during development in the last larval instar of rhodnius prolixus (hemiptera).the synthesis of ecdysteroids by prothoracic glands (pgs) of rhodnius prolixus was measured in vitro by radioimmunoassay in both male and female larvae following initiation of development in the last larval instar by a blood meal. neither ecdysteroid synthesis nor hemolymph titer differ between the sexes during the first few days following a blood meal. however, on day 4 the pgs of female larvae commence a surge of increased synthesis, while in males this surge does not commence until day 5. thi ...19892583469
a subpopulation of dorsal unpaired median neurons in the blood-feeding insect rhodnius prolixus displays serotonin-like immunoreactivity.we describe, for the first time in insects, the presence of serotonin-like immunoreactive dorsal unpaired median (dum) neurons. in unfed, untreated rhodnius prolixus, the cell bodies of these dum neurons displayed only faint serotonin-like immunofluorescence without any detectable fluorescence in the axons. there was, however, an extensive serotonin-like immunoreactive peripheral complex. we have enhanced the immunostaining of the cell bodies and axons of these dum neurons by using 5,7-dihydroxy ...19892681279
developmental and diurnal changes in ecdysteroid biosynthesis by prothoracic glands of rhodnius prolixus (hemiptera) in vitro during the last larval instar.the synthesis of ecdysteroids by prothoracic glands (pgs) of male last instar larvae of rhodnius prolixus was measured in vitro by radioimmunoassay throughout the course of larval-adult development. large and systematic changes in relative rates of synthesis occur during development. two bursts of elevated synthetic activity were found. the first commences as soon as development is initiated by a blood meal and lasts approximately 1 day. the second commences 4 days later and increases progressiv ...19892663631
pattern and composition of ionic currents around ovarioles of the hemipteran, rhodnius prolixus (stahl).two-dimensional vibrating probe analysis of extracellular currents around rhodnius prolixus ovarioles correlated with an earlier one-dimensional analysis but revealed asymmetrical circumferential current patterns and large tangential currents. na+, k+, and ca+2 have been tentatively identified as the major ions involved in these currents, with na+ being the major ion involved in current efflux.198929300571
the development of microtubular arrays in the germ tissue of an insect telotrophic ovary.the microtubular arrays characteristic of the trophic core and cords of the adult rhodnius prolixus ovary develop prior and during the larval--adult transformation. development of the microtubules was revealed by immunocytochemistry, electron microscopy and polyacrylamide electrophoresis and western blot analysis. microtubular arrays were first detected in the trophic cords and presumptive trophic core 6 days before the adult molt. cord microtubules increase in length and numbers as the trophic ...19892672416
biological characterization of a strain of trypanosoma cruzi chagas isolated from a human case of trypanosomiasis in california.in august 1982, the first autochthonous case of human american trypanosomiasis in california occurred. the isolate, the tuolumne strain of trypanosoma, was infective to young laboratory mice and capable of causing death or chronic disease in these animals. the morphology and mensural characteristics are described. this strain can develop in 2 species of triatominae native to california, triatoma protracta and t. rubida. the flagellates isolated from these insects were infective to vertebrate hos ...19892508500
in vitro cytotoxicity of rhodnius prolixus hemolytic factor and mellitin towards different trypanosomatids.trypanosoma cruzi strain y and clone dm28c and other trypanosomatids were exposed to two lytic agents, rhodnius prolixus hemolytic factor (rhf) and mellitin, in vitro. in both cases, the result was a significant decrease in the number of parasites after a 30-min treatment at 37 degrees c. rhf and mellitin had distinct activities on different strains and species of trypanosomatids. these observations suggest that rhf may be an important factor in selecting resistant strains of trypanosomes for de ...19892515905
action of activated 27,000 mr toxin from bacillus thuringiensis var. israelensis on malpighian tubules of the insect, rhodnius prolixus.the action of activated 27,000 mr toxin from bacillus thuringiensis var. israelensis (bti toxin) on malpighian tubules of rhodnius prolixus has been investigated. its binding to the tubules is slowed by low temperature but is not prevented even at 0 degree c. the binding is less effective at ph 10 than at ph7. pretreatment of the tubules with 0.1 mmol l-1 ouabain or bumetanide or 1 mumol l-1 5-hydroxytryptamine did not affect the toxicity of the toxin. the toxin causes very large changes in the ...19892632587
azadirachtin inhibits trypanosoma cruzi infection of its triatomine insect host, rhodnius prolixus. 19892657439
chagas' disease and its insect vector. effect of azadirachtin a on the interaction of a triatomine host (rhodnius prolixus) and its parasite (trypanosoma cruzi).the ed50 for moulting inhibition by injected azadirachtin a is for fourth instar larvae of all the triatomines, triatoma vitticepes, t. pseudomaculata, t. maculata, t. brasiliensis, t. lecticularis, t. matogrossensis, t. infestans, rhodnius prolixus. r. neglectus, r. robustus, panstrongylus megistus, and p. herrera in the range of 10-25 ng/larva. in rhodnius prolixus, the survival of t. cruzi was studied after treatment with the drug. if the trypomastigotes were fed in presence of 1.0 microgram ...19892663004
the effects of artificial diets on the anterior intestinal cell ultrastructure of rhodnius prolixus (hemiptera:reduviidae).mated female rhodnius prolixus were fed diets of washed rabbit erythrocytes (rbc), rabbit plasma, edestin (a plant storage protein) in ringer's or ringer's solution alone. all diets contained 1 mm atp. the effects of these diets on anterior intestinal cell ultrastructure were evaluated and compared to changes induced by normal blood feeding. separation of basal labyrinth membranes was induced earlier after ringer's-feeding than with all other diets. normal modifications of the rough endoplasmic ...19892668208
endpolyploidy and digestion in the midgut of rhodnius prolixus stål (hemiptera: reduviidae).the feulgen-dna content of the midgut cell nuclei of rhodnius prolixus is estimated by microspectrophotometry. midgut cells contain 23.35-32.16 pg dna/nucleus, which represents an increase of up to 26c when compared to diploid r. prolixus brain tissue. a high copy number cell population disappears from the anterior intestinal cells after feeding, and the presence of a new population of low copy number cells indicates that there may be some regeneration of the midgut epithelium in adult insects, ...19892688578
binding of lectins to culture and vector forms of trypanosoma rangeli tejera, 1920 (protozoa, kinetoplastida) and to structures of the vector gut.culture forms of trypanosoma rangeli could be agglutinated with canavalia ensiformis (con a) lectin and, less effectively with pisum sativum agglutinin (pea), at a concentration of 200 micrograms/ml. ricinus communis agglutinin i (rca i) agglutinated trypanosomes only if they were not previously washed with physiological ringer's solution. three other lectins did not react with the same parasite forms. direct or indirect lectin-gold labeling techniques were applied to lr-white embedded thin sect ...19892689636
trypanosoma (herpetosoma) leeuwenhoeki in choloepus hoffmanni and didelphis marsupialis of the pacific coast of colombia.trypanosoma (herpetosoma) leeuwenhoeki, originally described in panamanian sloths, was isolated from didelphis marsupialis (marsupialia) and choloepus hoffmanni (edentata) inhabiting the pacific coast of colombia. trypanosomes were characterized by their large blood forms (total length 51-53 microns), poor infectivity for mice, and lack of development in rhodnius prolixus. isoenzyme studies, with either strains or clones, revealed homogeneous profiles clearly distinct from trypanosoma cruzi and ...19892926591
trypanosoma (herpetosoma) rangeli tejera, 1920: study of the effects of the parasite on the vector.for evaluation of the possible pathogenicity of trypanosoma (herpetosoma) rangeli tejera, 1920 to the triatomid vector, first-stage nymphs of laboratory-bred insects were engorged upon albino mice showing average parasitemias of 2 x 10(6) and 2 x 10(5) trypanosomes/ml blood. the vector strains were: rhodnius prolixus ("new" strain), triatoma pallidipennis, and triatoma vitticeps. an "old" strain of r. prolixus (maintained 30 years in the laboratory) was also employed to check the effects of labo ...19892701258
tyrosine hydroxylase-like immunoreactivity in the brain of fifth instar rhodnius prolixus stål (hemiptera: reduviidae).the distribution of tyrosine hydroxylase-like immunoreactivity was mapped in whole-mount preparations of the brain of fifth instar rhodnius prolixus stål. immunoreactivity was limited to neuronal cell bodies and processes, which were distributed over both ventral and dorsal surfaces of the cns. the brain, excluding the optic lobes, contained about 160 tyrosine hydroxylase-like immunoreactive cells. each optic lobe contained two groups of small round cell bodies, which were too numerous to count. ...19901981216
a salivary vasodilator in the blood-sucking bug, rhodnius prolixus.1. salivary gland homogenates of the blood-sucking bug, rhodnius prolixus induced transient, dose-dependent relaxation of rabbit aortic preparations pre-constricted with 200 ng ml-1 noradrenaline, 1 microgram ml-1 histamine or 20 ng ml-1 angiotensin ii. such relaxations were less marked when the aorta was constricted by 60 mm kc1. these effects were observed with as little as 0.2 microgram ml-1 of crude salivary gland protein. 2. the vasodilator effect was endothelium-independent, abolished by 5 ...19902085715
comparative studies on the growth and reproductive performances of rhodnius prolixus reared on different blood sources.host blood source was found to affect both the development and the reproductive performance of rhodnius prolixus. the insects were reared on citrated human, rabbit, chicken, sheep and horse blood sources, through a membrane feeder, during an entire life cycle, from eggs to adults. development and reproduction in terms of the number of unfed insects, number of moulting, mortality intermoulting period, number of egg/female, conversion of blood into egg (mg meal/egg) and percentage of hatch as effe ...19902134703
cyclic amp in the malpighian tubule fluid and in the urine of rhodnius prolixus.we demonstrate the presence of cyclic adenosine monophosphate (camp) in the fluid secreted by isolated malpighian tubules of rhodnius prolixus. in addition, we show that fifth-instar r. prolixus excrete camp in the urine after a meal of human blood. nonstimulated isolated malpighian tubules secrete small amounts of camp that increase about 10-fold after the addition of 5-hydroxytryptamine (5-ht). 5-ht is known to mimic r. prolixus diuretic hormone. the present findings demonstrate that 5-ht also ...19902153089
development and interactions of trypanosoma rangeli in and with the reduviid bug rhodnius prolixus.two strains of trypanosoma rangeli and three strains of rhodnius prolixus were used in various combinations to transmit the trypanosomes via the reduviid bug. a persisting infection in the midgut lumen posterior to the stomach resulted in all 2,500 bugs being third and fourth instars. infectious, metacyclic forms developed exclusively in the salivary glands; forms excreted with bug feces were noninfectious to mice. the midgut epithelium was the main barrier to transmission of the parasite. in on ...19902186407
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