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the life history of echinostoma paraensei sp. n. (trematoda: echinostomatidae). 19676078607
schistosoma mansoni: temporary reduction of natural resistance in biomphalaria glabrata induced by irradiated miracidia of echinostoma paraensei. 1977891714
metacercarial cyst formation in vitro of echinostoma paraensei.cercariae of echinostoma paraensei lie and basch 1968 encysted normally in the presence of biomphalaria glabrata embryo (bge) cells in culture, partially in culture conditioned medium, and not at all in fresh culture medium alone. at the ultrastructural level the cyst is composed of 2 well defined regions. the outer cyst wall (ocw) is particulate to fibrous in nature, formed from secretory granules released from the cercarial tegument. membranous scrolls or rodlets secreted from the subtegumenta ...1977592031
tissue reactions induced by schistosoma mansoni in biomphalaria glabrata.in biomphalaria glabrata with a strong natural resistance, schistosoma mansoni sporocysts are rapidly encapsulated by granulocytes and killed, mainly by the strong phagocytic activity of the cells. irradiated echinostoma paraensei sporocysts seem able to suppress the function of the granulocytes. tissue reactions in snails with self-cure demonstrate: involvement of two types of cells, granulocytes and hyalinocyte-like cells; formation of amoeba-fibrous capsules; limited tendency of granulocytes ...19807436601
selective interference with granulocyte function induced by echinostoma paraensei (trematoda) larvae in biomphalaria glabrata (mollusca).various trematode larvae can interfere with the host snail's resistance to the same or unrelated trematode species, chiefly, it appears by interference with the function of the host's granulocytes. in biomphalaria glabrata infected with the trematodes, echinostoma paraensei, granulocytes lose their ability to encapsulate the larvae of trematodes to which the hosts were previously resistant. however, the granulocytes in these snails retain their ability to encapsulate injected latex spheres, or l ...19817328451
enzyme histochemical comparison of biomphalaria glabrata amebocytes with human granuloma macrophages.in fresh water snails, amebocytes are the principal cells that react to parasitic infection. ultrastructurally, amebocytes resemble mammalian macrophages. to clarify the relationship between amebocytes and macrophages, we compared the histochemical staining for seven enzymes in biomphalaria glabrata snail amebocytes, both in the amebocyte-producing organ (apo) and in the encapsulation reaction formed around parasite sporocysts with the staining in macrophages from the lymph nodes of patients wit ...19852981947
echinostoma paraensei: hemocytes of biomphalaria glabrata as targets of echinostome mediated interference with host snail resistance to schistosoma mansoni.earlier in vivo work by lie et al. (1977) indicated that the innate resistance of the 10r2 strain of biomphalaria glabrata to pr1 schistosoma mansoni could be interfered with if the snails were infected previously with another trematode, echinostoma paraensei. we have studied this interference phenomenon using in vitro methods in an attempt to understand its mechanistic basis. hemolymph, derived from 10r2 snails infected with e. paraensei for 14-28 days, killed 25% of s. mansoni sporocysts in vi ...19863087765
alterations in biomphalaria glabrata plasma induced by infection with the digenetic trematode echinostoma paraensei.alterations in the noncellular hemolymph components of m line biomphalaria glabrata snails infected with the trematode echinostoma paraensei for 1, 2, 4, 8, 15, 30, or 60 days were monitored by direct microscopical examination, and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) in conjunction with quantitative densitometry. a prominent particulate substance was first noted in the hemolymph of infected snails at 1 day postexposure (pe), persisted through day 15, and subsi ...19873598800
the effect of size of m line biomphalaria glabrata on the course of development of echinostoma paraensei.m line biomphalaria glabrata snails of 4-, 6-, 8-, 10-, 12-, or 20-mm shell diameter were individually exposed to 10 miracidia each of echinostoma paraensei. snails 10 mm in size or larger were found to be significantly less likely to harbor intraventricular sporocysts than snails in smaller size categories. the percentage of snails with intraventricular sporocysts that also developed hemocyte encapsulation responses generally increased with snail size, whereas the number of snails that ultimate ...19873437347
immunocytochemical localization of regulatory peptides in six species of trematode parasites.1. frozen and paraffin sections of six species of trematodes: schistosoma mansoni, s. mattheei, s. japonicum, schistosomatium douthitti, echinostoma paraensei and fasciola hepatica have been incubated with antisera against leu-enkephalin, fmrf-amide, gastrin-17, luteinizing hormone releasing hormone, neurotensin, oxytocin, prolactin, substance p, thyroid stimulating hormone and cholecystokinin, using indirect immunofluorescence and biotin-avidin horseradish peroxidase detection systems. 2. of th ...19882905970
differential adherence of m line biomphalaria glabrata hemocytes to schistosoma mansoni and echinostoma paraensei larvae, and experimental manipulation of hemocyte binding.the ability of m line strain biomphalaria glabrata hemocytes to adhere to mother sporocysts (ms) of pr1 schistosoma mansoni or to ms or daughter rediae (dr) of echinostoma paraensei was studied using an in vitro hemocyte adherence assay. hemocytes were significantly more likely to bind to s. mansoni ms than to e. paraensei ms or dr. hemocyte adherence to e. paraensei ms or dr was significantly increased if glutaraldehyde-fixed larvae were used as targets. also, e. paraensei ms pretreated with th ...19892768830
effects of infection with echinostoma paraensei on the circulating haemocyte population of the host snail biomphalaria glabrata.circulating haemocytes from echinostoma paraensei-infected m line biomphalaria glabrata snails, or from age- and size-matched control snails, were studied on plastic slides with phase-contrast optics. granulocytes, hyalinocytes, and round cells were consistently present; granulocytes were further categorized as 'fully spread' (fs) or 'partially spread' (ps). among control snails, the relative percentage and estimated number/mm3 of round cells declined significantly with increased snail size, and ...19892717217
phagocytic activity of hemocytes of m-line biomphalaria glabrata snails: effect of exposure to the trematode echinostoma paraensei.the phagocytic activity of hemocytes from 6-8-mm m-line biomphalaria glabrata snails was studied in an in vitro assay using glutaraldehyde-fixed sheep erythrocytes (srbc) as target cells. for individual snails, the percentage of hemocytes ingesting srbc during a 1-hr interval, termed the phagocytic activity index (pai), was determined. hemocytes from snails infected for 1 day with echinostoma paraensei had a slightly elevated pai, but at both 8 and 30 days postexposure (dpe), hemocytes from infe ...19892926593
humoral response of the snail biomphalaria glabrata to trematode infection: observations on a circulating hemagglutinin.the hemolymph of invertebrates often contains molecules that agglutinate vertebrate erythrocytes and that may function as humoral mediators of "non-self" recognition. the objectives of this study were to 1) determine if exposure of m line or 10-r2 strain biomphalaria glabrata snails to infection with the trematodes echinostoma paraensei and schistosoma mansoni could increase agglutinating activity in snail hemolymph, and 2) identify particular hemolymph molecules with such activity. in some host ...19902394975
lectin-binding properties of the surfaces of in vitro-transformed schistosoma mansoni and echinostoma paraensei sporocysts.as carbohydrates on the surfaces of sporocysts of digenetic trematodes may be targets of attack by the molluscan internal defense system, the lectin-binding patterns of living, in vitro-transformed sporocysts of schistosoma mansoni and echinostoma paraensei were characterized. schistosoma mansoni sporocysts specifically bound 8 and e. paraensei 6 of 11 lectins examined. sporocysts of the 2 species responded differently to 7 of the 11 lectins. lectins inhibitable by mannose, galactose, and n-acet ...19911919922
excretory-secretory products of echinostoma paraensei sporocysts mediate interference with biomphalaria glabrata hemocyte functions.miracidia of echinostoma paraensei were cultured in medium containing 14c-labeled amino acids, allowed to transform into sporocysts, and their excretory/secretory products (e-s) were collected and characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. effects of e-s on hemocytes of biomphalaria glabrata were also assessed. e-s collected during day 1 of culture (e-s1) contained several polypeptides, none of which were labeled, suggesting that e-s1 are larg ...19921738052
effects of excretory-secretory products of echinostoma paraensei larvae on the hematopoietic organ of m-line biomphalaria glabrata snails.responses of the hematopoietic organ (ho) in biomphalaria glabrata snails to extracts and excretory-secretory (e-s) products of echinostoma paraensei larvae were studied to understand the ho-activating mechanism. m-line b. glabrata snails were injected with materials from e. paraensei larvae, and the size of the ho was ascertained in histological sections. the size of ho in snails injected with extracts and e-s products from sporocysts and rediae was significantly larger than that in snails inje ...19921597797
echinostoma paraensei and schistosoma mansoni: adherence of unaltered or modified latex beads to hemocytes of the host snail biomphalaria glabrata.hemocytes derived from a strain (13-16-r1) of biomphalaria glabrata resistant to schistosoma mansoni were significantly more likely to bind untreated latex beads than hemocytes from the schistosome-susceptible m line strain. beads preincubated in 13-16-r1 plasma were more readily bound by both 13-16-r1 and m line hemocytes than beads preincubated in m line plasma. beads preincubated in plasma derived from snails of either strain infected with the trematode echinostoma paraensei were more readily ...19921516670
carbohydrate-binding plasma proteins from the gastropod biomphalaria glabrata: strain specificity and the effects of trematode infection.as lectins are believed to mediate non-self-recognition in molluscs, carbohydrate-binding proteins (cbp) from the circulating plasma of the gastropod biomphalaria glabrata were harvested by affinity chromatography using six different monosaccharides as ligands. pools of plasma were derived from b. glabrata of either the m line strain, which is susceptible to infection with the pr1 strain of the digenetic trematode schistosoma mansoni, or from the 13-16-r1 strain, which is resistant to infection. ...19921330758
production of heterogeneous carbohydrate-binding proteins by the host snail biomphalaria glabrata following exposure to echinostoma paraensei and schistosoma mansoni.hemolymph lectins may play an important role in the internal defense responses of gastropods to parasites. two groups of known carbohydrate-binding polypeptides, of 150-220 kda (designated as group 1 molecules, or g1m) and of 75-130 kda (group 2 molecules, or g2m), were harvested from pooled plasma samples of biomphalaria glabrata using affinity chromatography and examined using 2-dimensional electrophoresis. plasma samples were derived from control snails or snails exposed 8 days earlier to the ...19938501600
elevated agglutination titres in plasma of biomphalaria glabrata exposed to echinostoma paraensei: characterization and functional relevance of a trematode-induced response.production of elevated haemolymph agglutination titres by biomphalaria glabrata following exposure to echinostoma paraensei miracidia was investigated, to characterize this parasite-induced response and to understand its functional relevance. both the dose of infection (1, 10 or 100 miracidia per snail) or the number of separate exposures to infection (between one and three, over a 4 or 8 day interval) were varied, and assuming a threshold dosage (10 miracidia per snail or higher) was exceeded, ...19948152851
biomphalaria glabrata hemolymph lectins: binding to bacteria, mammalian erythrocytes, and to sporocysts and rediae of echinostoma paraensei.polyclonal antibodies were raised in rabbits to two groups of diffusely staining m line biomphalaria glabrata plasma polypeptides, of 150-210 and 70-120 kda, designated as group 1 molecules (g1m) and group 2 molecules (g2m), respectively. g1m and g2m are known to increase in abundance and to become more diverse following infection of b. glabrata with the digenetic trematode echinostoma paraensei. these antibodies were used in conjunction with immunoblotting and slot blotting procedures to docume ...19948064176
a time-lapse study of interactions between echinostoma paraensei intramolluscan larval stages and adherent hemocytes from biomphalaria glabrata and helix aspersa.in vitro interactions between intramolluscan stages (sporocyst, daughter rediae, and metacercariae) of the trematode parasite echinostoma paraensei and adherent hemocytes from the gastropods biomphalaria glabrata (intermediate host) and helix aspersa (non-host) were visualized by time-lapse videomicroscopy. hemocytes of either species not exposed to e. paraensei displayed extensive mobility and activity of cellular extensions. image analysis disclosed no significant change in the total surface a ...19947931907
the mating behaviour of echinostoma paraensei grown in mice.adults of echinostoma paraensei grown in mice were exposed to 3-h-tyrosine and transplanted to uninfected mice singly or with unexposed worms. the presence of sperm labelled with the radioactive tyrosine in the seminal receptacles of labelled and unlabelled worms recovered after 5 days indicated the mating pattern of this species. of nine isolated, labelled worms recovered, four had self-inseminated (44%). of the 39 unlabelled found with eight labelled worms, only eight exhibited labelled sperm ...19968960198
fate of schistosoma mansoni in biomphalaria obstructa.histological sections of biomphalaria obstructa snails exposed to miracidia of schistosoma mansoni revealed that although viable sporocysts occurred in 6 of 9 snails at 3 days postexposure (dpe), all were dead by 7 dpe. most dead sporocysts appeared to have degenerated slowly rather than having been killed by host hemocytic responses, which were minimal. what appeared to be amorphous remnants of sporocysts could still be found at 31 dpe. in 7 of 10 snails infected simultaneously with s. mansoni ...19968885882
molecular characterization of echinostoma caproni and e. paraensei by random amplification of polymorphic dna (rapd) analysis.genomic dna from echinostoma caproni and echinostoma paraensei was amplified by the polymerase chain reaction using primers (5'-tcgtagccaa and 5'-tcacgatgca), originally found to differentiate species and strain of schistosoma. the 2 putative species of echinostoma produced distinct banding patterns clearly distinguishable from one another, thereby suggesting that rapd (random amplification of polymorphic dna) analysis may be useful for the identification of echinostome strains and species previ ...19968604120
a comparison of the adult and miracidial stages of echinostoma paraensei and e. caproni.adult echinostoma paraensei and echinostoma caproni were grown in outbred mice and golden hamsters to compare size, growth rates, infectivity, and habitat selection. antagonistic responses between the 2 species were investigated by concurrent infections in mice. miracidial stages were compared for developmental stages, hatching responses, and behaviour to light and gravity. size differences and growth rates were significantly different in both mice and hamsters. mice proved to be better hosts fo ...19969198594
a family of fibrinogen-related proteins that precipitates parasite-derived molecules is produced by an invertebrate after infection.after infection with the digenetic trematode echinostoma paraensei, hemolymph of the snail biomphalaria glabrata contains lectins comprised of 65-kda subunits that precipitate polypeptides secreted by e. paraensei intramolluscan larvae. comparable activity is lacking in hemolymph of uninfected snails. three different cdnas with sequence similarities to peptides derived from the 65-kda lectins were obtained and unexpectedly found to encode fibrinogen-related proteins (freps). these freps also con ...19979238039
comparative studies on excystation and morphological features of the metacercariae of echinostoma paraensei and e. caproni.studies were done to determine specific differences between the metacercariae of echinostoma paraensei and e. caproni. the percentage of excystation of e. caproni in an alkaline trypsin-bile salts medium was about 6x greater than that of e. paraensei. the body and acetabular length of excysted metacercariae of e. caproni were significantly greater (student's t-test, p < 0.05) than those of e. paraensei. the length and width of encysted metacercariae of e. caproni were significantly greater than ...19979292305
susceptibility of biomphalaria glabrata to infection with echinostoma paraensei: correlation with the effect of parasite secretory-excretory products on host hemocyte spreading.susceptibility of the snail biomphalaria glabrata to infection with the digenetic trematode echinostoma paraensei was correlated with the ability of secretory-excretory products (sep) derived from sporocysts of this parasite to interfere with the spreading behavior of host hemocytes in an in vitro assay. in 15 separate experiments, the prevalence of infection achieved by miracidia was positively correlated (c.c. = 0.779, p < 0.001) with the ability of in vitro-transformed sporocysts derived from ...19989446739
mitochondrial nd1 gene sequences used to identify echinostome isolates from australia and new zealand.echinostomes were collected in australia and new zealand as cercariae, metacercariae or adults. using dna sequences from the mitochondrial nd1 gene echinostoma revolutum and echinostoma paraensei were discovered in australia. the presence of a further five, as yet unidentified, echinostome species was inferred in northern australia and a further isolate, closely allied to e. revolutum, occurs in new zealand. nd1 sequences of species within the genus diverge from each other by 9.6-30.8%. sequence ...19989559367
comparative ultrastructure study of lamellar gastrodermal projections in echinostoma paraensei, e. caproni, and e. trivolvis (trematoda : echinostomatidae).a comparative ultrastructure study using transmission electron microscopy (tem) of ultrathin sections, freeze-fracture replication, and scanning electron microscopy (sem) was conducted on the gastrodermal lamellar microvilli in adults of echinostoma paraensei, e. caproni, and e. trivolvis. lamellar projections observed by sem were mainly planiform and rhomboidal or paddle-shaped, and they were commonly seen in the three species. the distal margins of these lamellae were mainly smooth in e. parae ...199910431728
evidence from two planorbid snails of a complex and dedicated response to digenean (echinostome) infection.the planorbid snail biomphalaria glabrata responded to exposure to either the compatible digenetic trematode echinostoma paraensei or the incompatible species echinostoma trivolvis by producing increased amounts of several distinctive plasma polypeptides. these polypeptides characteristically precipitated from plasma when mixed with secreted-excreted products (sep) of sporocysts or rediae from either digenean species. in contrast, control snails, or snails that had been wounded or infected with ...199910581618
analysis of messages expressed by echinostoma paraensei miracidia and sporocysts, obtained by random est sequencing.a lambdazap express cdna library was constructed with mrna obtained from immature miracidia within eggs, hatched miracidia, and sporocysts of echinostoma paraensei. this cdna library was amplified and 213 expressed sequence tag (est) sequences (averaging 466 nucleotides in length) were obtained. the mean percentage of unresolved bases within the est sequences was 0.4%, ranging from 0 to 4.6%. the 213 ests represent 151 unique messages. blast (version 2.0.8) analysis disclosed that 64 unique e. p ...200010701565
comparative ultrastructure of eggs in echinostoma paraensei, e. caproni, and e. trivolvis (trematoda: echinostomatidae).the 37-collar-spined echinostomes echinostoma paraensei, e. caproni, and e. trivolvis are digeneans that live in the intestine of small mammals and birds. comparative studies of the eggs of these species were done using light microscopy (lm), scanning electron microscopy (sem), and transmission electron microscopy (tem). the egg of e. caproni was the largest of the three species studied, whereas the egg of e. trivolvis was the smallest in both length and width. the sem study showed differences i ...200010836518
mechanisms underlying digenean-snail specificity: role of miracidial attachment and host plasma factors.digenetic trematodes usually show a high degree of specificity for their molluscan intermediate hosts. a panel of 4 digenean species (echinostoma paraensei, e. trivolvis, schistosoma mansoni, and schistosomatium douthitti) and 5 snail species (biomphalaria glabrata, helisoma trivolvis, lymnaea stagnalis, stagnicola elodes, and helix aspersa representing 3 gastropod families) was used to assess the relative contributions of miracidial behavior, host plasma osmolality, and host plasma factors in d ...200011128473
a comparative study of mechanisms underlying digenean-snail specificity: in vitro interactions between hemocytes and digenean larvae.a panel of 4 digenetic trematode species (echinostoma paraensei, e. trivolvis, schistosoma mansoni, and schistosomatium douthitti) and 5 snail species (biomphalaria glabrata, helisoma trivolvis, lymnaea stagnalis, stagnicola elodes, and helix aspersa) was examined to determine if known patterns of host specificity could be explained by the tendency of digenean larvae to be bound by snail hemocytes, or by the ability of larvae to influence the spreading behavior of hemocytes. in short-term (1 hr) ...200011128474
structure of two frep genes that combine igsf and fibrinogen domains, with comments on diversity of the frep gene family in the snail biomphalaria glabrata.upon exposure to infection with digenetic trematodes such as echinostoma paraensei, the freshwater snail biomphalaria glabrata produces increased quantities of hemolymph lectins, some of which are unique polypeptides containing both immunoglobulin superfamily (igsf) and fibrinogen domains. these unusual lectins have been termed fibrinogen-related proteins (freps), and recognize and precipitate digenean antigens. we here report 11 distinct frep-encoding sequences from b. glabrata, and provide the ...200111376947
changes on schistosoma mansoni (digenea: schistosomatidae) worm load in nectomys squamipes (rodentia: sigmodontinae) concurrently infected with echinostoma paraensei (digenea: echinostomatidae).the water rat, nectomys squamipes, closely involved in schistosomiasis transmission in brazil, has been found naturally infected simultaneously by schistosoma mansoni and echinostoma paraensei. laboratory experiments were conducted to verify parasitic interaction in concurrent infection. it was replicated four times with a total of 42 water rats and essayed two times with 90 mice pre-infected with e. paraensei. rodents were divided into three groups in each replication. a wild strain recently is ...200111586449
description of the adult worms of a new brazilian isolate of echinostoma paraensei (platyhelminthes:digenea) from its natural vertebrate host nectomys squamipes by light and scanning electron microscopy and molecular analysis.echinostoma paraensei lie and basch, 1967 (echinostomatidae:platyhelminthes), a 37 collar spine echinostome of the "revolutum group", has been used extensively as a model organism to study the interactions of digenetic trematodes with both their snail and vertebrate hosts. this worm was first isolated from the snail biomphalaria glabrata from belo horizonte (bh isolate), minas gerais state, brazil, by lie and basch [j parasitol (1967) 53:1192-1199]. the natural definitive host for the bh isolate ...200111688891
biological aspects of a new isolate of echinostoma paraensei (trematoda: echinostomatidae): susceptibility of sympatric snails and the natural vertebrate host.a new isolate of echinostoma paraensei (lie & basch, 1967) was obtained from a natural vertebrate host, the water rat nectomys squamipes. relationships with sympatric snails, biomphalaria glabrata; physa marmorata and lymnaea columella, as well as allopatric snails and the definitive hosts n. squamipes, mus musculus, rattus norvegicus, mesocricetus auratus and birds were investigated. e. paraensei developed in all sympatric snail species following exposure to one or five miracidia. p. marmorata ...200111688893
germinal elements and their development in echinostoma caproni and echinostoma paraensei (trematoda) miracidia.among the large cells located in the posterior of echinostoma caproni and e. paraensei miracidia are secretory cells, germinal cells (gc), and undifferentiated cells. secretory cells do not give rise to progeny, whereas gc do. undifferentiated cells develop into gc that can also divide to produce embryos. cleavage of gc of e. caproni occurs only after the parasite has entered the snail host and develops into a sporocyst. with e. paraensei, gc are larger than noted for e. caproni, and in 3 of 23 ...200111695384
parasite-responsive igsf members in the snail biomphalaria glabrata: characterization of novel genes with tandemly arranged igsf domains and a fibrinogen domain.two novel genes of the immunoglobulin superfamily (igsf), frep3 and frep7, are reported from the snail biomphalaria glabrata, a prominent intermediate host of the human parasite schistosoma mansoni. they resemble other b. glabrata genes that encode fibrinogen-related proteins (freps), but differ in that they encode proteins with two tandemly arranged igsf domains followed by a c-terminal fibrinogen domain. freps are hemolymph proteins that increase in abundance following exposure to a digenetic ...200111797103
characterization of sm14 related components in different helminths by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting analysis.sm14 was the first fatty acid-binding protein homologue identified in helminths. thereafter, members of the same family were identified in several helminth species, with high aminoacid sequence homology between them. in addition, immune crossprotection was also reported against fasciola hepatica infection, in animals previously immunized with the schistosoma mansoni vaccine candidate, r-sm14. in the present study, data on preliminary sodium dodecyl sulphate-polyacrylamide gel electrophoresis and ...200212426606
morphology of the rediae of echinostoma paraensei (trematoda: echinostomatidae) from its intermediate host lymnaea columella (mollusca, gastropoda).the morphology of the rediae of echinostoma paraensei obtained from lymnaea columella was studied using light, scanning and transmission electron microscopy. the measurements of the mature rediae differ from those described originally, and the taxonomic importance of the ambulatory buds and papilliform process is discussed. uniciliated papillae were observed in the mouth region. the birth papilla is a bulb-like structure, well defined at the anterior end of the body of the rediae, which opens th ...200415127294
light and scanning electron microscopy of the miracidium of echinostoma paraensei (trematoda, echinostomatidae).echinostoma paraensei was described 1967 by lie and basch. recently its natural definitive host, the aquatic rodent nectomys squamipes, endemic in brazil, was identified. as most of the echinostomatids, this species presents a zoonotic potential. the morphology and topography of the e. paraensei miracidium obtained from adult worms collected from the natural definitive host n. squamipes is described by light and electron microscopy. the arrangement and the dimensions of the epidermal plates are ...200415135866
echinostoma paraensei: differential gene transcription in the sporocyst stage.the sporocyst stage of trematode development plays the crucial role of establishing a successful infection in the molluscan intermediate host. due to the small size and presence of this stage within the tissues of the host, much of our current knowledge of sporocyst biology relies on cultured specimens. to gain insight into the transcriptional patterns of early sporocysts, suppression subtractive hybridization was employed to identify 69 unique expressed sequence tags likely to be upregulated in ...200515687016
differential expression of frep genes in two strains of biomphalaria glabrata following exposure to the digenetic trematodes schistosoma mansoni and echinostoma paraensei.fibrinogen-related proteins (freps) are hypothesized to function in non-self-recognition in the snail biomphalaria glabrata. to investigate this assumption, the expression of four members of the frep gene family was studied using quantitative pcr at 0.5-16 days following exposure of m line and bs-90 strain b. glabrata to echinostoma paraensei and schistosoma mansoni. both strains react to, but fail to eliminate e. paraensei. only the bs-90 strain is immunologically resistant to s. mansoni. both ...200515859234
ultrastructure of the miracidium of echinostoma paraensei lie and basch, 1967 (trematoda, echinostomatidae).the morphology of echinostoma paraensei was studied using transmission electron microscopy. the terebratorium region has many electrondense secretory granules and many folds on the surface. the epidermal cells that cover the larval body have unique nuclear morphology, many mitochondria and vesicles being attached to the interepidermal ridges by a septate junction. the cilia present the organization 9 + 2 and a typical structure with a shaft, axosome, basal body and rootlet. below the epidermal c ...200516151745
biological variation between two brazilian geographical isolates of echinostoma paraensei.the biological behaviour and morphometric data from two allopatric isolates of echinostoma paraensei (rio bonito - rb and sumidouro - su) collected from naturally infected nectomys squamipes from two secluded atlantic forest fragments were studied. mice that had been experimentally infected with ten encysted metacercariae of each isolate were monitored weekly in two trials to analyse worm burden and the kinetics of worm distribution along the intestine. the total number of uterine eggs, wet weig ...200516336719
manganese superoxide dismutase from biomphalaria glabrata.the investigation of the response of biomphalaria glabrata snails to echinostoma paraensei (digenea) at 2 days post-exposure by suppression subtractive hybridization yielded a partial sequence of the anti-oxidant enzyme manganese superoxide dismutase (mnsod). full-length mnsod (669nt) from m line and bs-90 strains of b. glabrata differed by one synonymous nucleotide replacement. b. glabrata has 1-4 mnsod loci (southern hybridization). both snail strains expressed mnsod at equal baseline levels ( ...200516081093
in vivo and in vitro knockdown of frep2 gene expression in the snail biomphalaria glabrata using rna interference.rna interference (rnai) is reported here for the first time for biomphalaria glabrata, the snail intermediate host for the human parasite schistosoma mansoni. the fibrinogen-related protein 2 (frep2) gene, normally expressed at increased levels following exposure to digenetic trematode parasites, such as s. mansoni or echinostoma paraensei, was targeted for knockdown. double-stranded rna (dsrna) corresponding to specific regions of the frep2 gene was introduced into snails by direct injection in ...200616442620
helminth communities of nectomys squamipes naturally infected by the exotic trematode schistosoma mansoni in southeastern brazil.the water rat nectomys squamipes is endemic in brazil and found naturally infected with schistosoma mansoni. helminth communities, their prevalences, intensity of infection and abundance in n. squamipes in an endemic area of schistosomiasis in the state of rio de janeiro, brazil were studied. four species of nematodes (physaloptera bispiculata, syphacia venteli, hassalstrongylus epsilon and litomosoides chagasfilhoi) were recovered in 85.3%, two trematodes (schistosoma mansoni and echinostoma pa ...200617125546
characterization of immune genes from the schistosome host snail biomphalaria glabrata that encode peptidoglycan recognition proteins and gram-negative bacteria binding protein.peptidoglycan (pgn) recognition proteins (pgrps) and gram-negative bacteria binding proteins (gnbps) play an essential role in toll/imd signaling pathways in arthropods. the existence of homologous pathways involving pgrps and gnbps in other major invertebrate phyla such as the mollusca remains unclear. in this paper, we report four full-length pgrp cdnas and one full-length gnbp cdna cloned from the snail biomphalaria glabrata, the intermediate host of the human blood fluke schistosoma mansoni, ...200717805526
fibrinogen-bearing protein genes in the snail biomphalaria glabrata: characterization of two novel genes and expression studies during ontogenesis and trematode infection.all fibrinogen (fbg)-bearing proteins documented to date in the freshwater snail biomphalaria glabrata, the intermediate host of the human blood fluke schistosoma mansoni, possess the same molecular structure; one or two immunoglobin superfamily (igsf) domains at the n-terminus and a fbg domain at the c-terminus (named as fbg-related protein (frep)). here we report two novel genes that encode fbg-bearing proteins from b. glabrata. different from all known freps, the first gene encodes a protein ...200818417215
expression profiling and binding properties of fibrinogen-related proteins (freps), plasma proteins from the schistosome snail host biomphalaria glabrata.a growing body of evidence suggests an important role for fibrinogen-like proteins in innate immunity in both vertebrates and invertebrates. it has been shown that fibrinogen-related proteins (freps), plasma proteins present in the freshwater snail biomphalaria glabrata, the intermediate host for the human blood fluke schistosoma mansoni, are diverse and involved in snail innate defense responses. to gain further insight into the functions of freps, recombinant frep proteins (rfreps) were produc ...200818562576
schistosomin from the snail biomphalaria glabrata: expression studies suggest no involvement in trematode-mediated castration.by inhibiting reproductive hormones, the neuropeptide schistosomin produced by the snail lymnaea stagnalis plays an essential role in parasitic castration mediated by the schistosome parasite trichobilharzia ocellata during late stage infection. here we report on the presence and expression of schistosomin in the snail biomphalaria glabrata, a prominent intermediate host of the parasite schistosoma mansoni, one of the causative agents of human schistosomiasis. the deduced amino acid (aa) sequenc ...200919393164
physiological changes in lymnaea columella (say, 1817) (mollusca, gastropoda) in response to echinostoma paraensei lie and basch, 1967 (trematoda: echinostomatidae) infection.the physiological interaction between the digenean echinostoma paraensei larvae and the intermediate snail host lymnaea columella was studied. the carbohydrate content was significantly altered in the digestive gland tissue of snails, decreasing after 20 days postinfection. at the end of the prepatent period, the carbohydrate content was reduced by 60% when compared to uninfected snails. the total protein was reduced by 80.01% and 76.42% in the hemolymph and digestive gland, respectively. the en ...200919777261
differential transcriptomic responses of biomphalaria glabrata (gastropoda, mollusca) to bacteria and metazoan parasites, schistosoma mansoni and echinostoma paraensei (digenea, platyhelminthes).a 70-mer-oligonucleotide-based microarray (1152 features) that emphasizes stress and immune responses factors was constructed to study transcriptomic responses of the snail biomphalaria glabrata to different immune challenges. in addition to sequences with relevant putative id and gene ontology (go) annotation, the array features non-immune factors and unknown b. glabrata ests for functional gene discovery. the transcription profiles of b. glabrata (3 biological replicates, each a pool of 5 snai ...201019962194
time series analysis of the transcriptional responses of biomphalaria glabrata throughout the course of intramolluscan development of schistosoma mansoni and echinostoma paraensei.successful colonization of a compatible snail host by a digenetic trematode miracidium initiates a complex, proliferative development program requiring weeks to reach culmination in the form of production of cercariae which, once started, may persist for the remainder of the life span of the infected snail. how are such proliferative and invasive parasites able to circumvent host defenses and establish chronic infections? using a microarray designed to monitor the internal defense and stress-rel ...201020083115
the effect of early infection with echinostoma paraensei on the interaction of schistosoma mansoni with biomphalaria glabrata and biomphalaria tenagophila.infection caused by the trematode echinostoma paraensei has been shown to interfere in the natural resistance to infection by schistosoma mansoni. biomphalaria glabrata is susceptible to infection, while taim isolate biomphalaria tenagophila is resistant to infection by s. mansoni. these two snail species were assessed for infection with e. paraensei two days after exposure to s. mansoni miracidia. the number of b. tenagophila and b. glabrata infected with e. paraensei was lower in co-infected g ...201020721499
role for a somatically diversified lectin in resistance of an invertebrate to parasite infection.invertebrates lack adaptive immune systems homologous to those of vertebrates, yet it is becoming increasingly clear that they can produce diversified antigen recognition molecules. we have previously noted that the snail biomphalaria glabrata produces a secreted lectin, fibrinogen-related protein 3 (frep3), unusual among invertebrate defense molecules because it is somatically diversified by gene conversion and point mutation. here we implicate frep3 in playing a central role in resistance to a ...201021084634
biochemical and histological responses of rattus novergicus (wistar) infected by echinostoma paraensei (trematoda: echinostomatidae).tests were performed to evaluate the biochemical alterations in rattus norvegicus after infection by the intestinal trematode echinostoma paraensei. the rodents received 150 metacercariae each, serum samples were collected and the parasite load was quantified weekly until the fifth week of infection. the levels of aspartate aminotransferase (ast), alanine aminotransferase (alt), alkaline phosphatase (alkp), gamma-glutamyl transferase (ggt), bilirubin, glucose, total proteins and fractions and he ...201121255935
lipid levels in biomphalaria glabrata infected with different doses of echinostoma paraensei miracidia.the effect of experimental exposure of biomphalaria glabrata to different doses (5 and 50) of echinostoma paraensei miracidia on the total levels of cholesterol and triglycerides circulating in the hemolymph and the neutral lipids in the digestive gland-gonad (dgg) complex were studied. the snails were dissected one, two, three and four weeks after infection to collect the hemolymph and dgg tissue, to measure the levels of cholesterol and triglycerides in the hemolymph and neutral lipids in the ...201121439956
biochemical profile of biomphalaria glabrata (mollusca: gastropoda) after infection by echinostoma paraensei (trematoda: echinostomatidae).the effect of infection by echinostoma paraensei on the activity of the enzymes alanine aminotransferase (alt) and aspartate aminotransferase (ast) and the concentration of total proteins, uric acid and urea in the hemolymph of biomphalaria glabrata were investigated after exposure to five or 50 miracidia. the biochemical concentrations were measured weekly until the end of the fourth week after exposure. there was a significant decrease in the concentrations of total proteins in the snails expo ...201121537991
development of the reproductive system of echinostoma paraensei in mesocricetus auratus analyzed by light and confocal scanning laser microscopy.this study was performed to gain insight into the maturation of the reproductive system of echinostoma paraensei worms grown in an early infection of mesocricetus auratus. hamsters were infected with 100 metacercariae and necropsied on days 3, 5, 7, 10 and 14 post infection (dpi). recovered flukes stained with hydrochloric carmine were preserved as whole mounts and analyzed by light and confocal scanning laser microscopy. the average worm recovery was 43.7 per host. images of the male and female ...201121554877
influence of echinostoma paraensei (lie and basch, 1967) infection on the calcium content in biomphalaria glabrata (say, 1818).the calcium content in the hemolymph and shell of biomphalaria glabrata (say, 1818) was determined after exposure to different parasite burdens (5 and 50 miracidia) of echinostoma paraensei (lie and basch, 1967). the snails were dissected 1, 2, 3, and 4weeks after infection to collect the hemolymph and shell. an increase in calcemia was observed in snails infected with both miracidial doses. a significant decrease in the calcium ions in the shell was observed, coinciding with the calcemia peak i ...201121820434
changes in the reproductive biology of biomphalara glabrata infected with different doses of echinostoma paraensei miracidia.the egg-laying rate, number of egg masses, number of eggs/mass, number of eggs hatched/snail and egg viability of biomphalaria glabrata exposed to different doses (5 and 50) of echinostoma paraensei miracidia were analyzed as indicators of reproductive activity. polystyrene plates were placed in aquariums containing the snails and every other day for four weeks after infection the plates were removed to count the number of egg masses and eggs laid. after this, the plates were numbered individual ...201120850448
effect of praziquantel on adult echinostoma paraensei worms in experimentally infected mice.echinostomiasis is a food-borne intestinal, snail-mediated parasitosis caused principally by ingestion of snails infected with digenean trematodes of the echinostoma genus. the treatment and control of trematodiasis is usually done by administration of praziquantel (pzq). in this study, we evaluated the effect on echinostoma paraensei of different doses of praziquantel through analysis of morphological parameters using light microscopy, scanning electron microscopy, and confocal scanning laser m ...201222249761
evaluation of praziquantel effects on echinostoma paraensei ultrastructure.echinostomiasis is a food-borne, intestinal, zoonotic, snail-mediated helminthiasis caused by digenean trematodes of the family echinostomatidae with seven species of the genus echinostoma infecting humans or domestic and wildlife animals. echinostoma paraensei is a peristomic 37-collar-spined echinostome belonging to the "revolutum group". praziquantel (pzq) is the drug of choice for treatment and control of human schistosomiasis and food-borne trematodiasis. in the present study we used scanni ...201223312867
haematological alterations in rattus norvegicus (wistar) experimentally infected with echinostoma paraensei (trematoda: echinostomatidae).laboratory rats (rattus norvegicus) were infected with echinostoma paraensei (trematoda: echinostomatidae). the rodents received 150 metacercariae each and blood samples were collected weekly until the fifth week of infection. the blood samples were analyzed for determination of haematocrit, total red blood cells with their dimensions, haemoglobin and haematimetric index (mean corpuscular volume, mcv; mean corpuscular haemoglobin, mch; and mean corpuscular haemoglobin concentration, mchc) and pl ...201222579577
a somatically diversified defense factor, frep3, is a determinant of snail resistance to schistosome infection.schistosomiasis, a neglected tropical disease, owes its continued success to freshwater snails that support production of prolific numbers of human-infective cercariae. encounters between schistosomes and snails do not always result in the snail becoming infected, in part because snails can mount immune responses that prevent schistosome development. fibrinogen-related protein 3 (frep3) has been previously associated with snail defense against digenetic trematode infection. it is a member of a l ...201222479663
in vitro excystation of echinostoma paraensei (digenea: echinostomatidae) metacercariae assessed by light microscopy, morphometry and confocal laser scanning microscopy.trypsin and bile salts have been identified as important triggers for excystation of echinostoma metacercariae. although excystation in trematodes is a well-known phenomenon, some morphological developmental changes remain to be elucidated. in order to gain further insight into the in vitro development of metacercariae, we assayed different cultivating conditions: 0.5% trypsin and 0.5% bile salts; 1% trypsin and 1% bile salts; 1% trypsin and 0.5% bile salts; 0.5% bile salts; or 0.5% trypsin. by ...201324184079
a simple and efficient method to observe internal structures of helminths by scanning electron microscopy.morphological studies of helminths by scanning electron microscopy are generally limited to the external topography of the organisms. in this work, we present a simple technique using ethanol as a cryoprotectant without postfixation in osmium tetroxide that allows for observation of the inner organization of helminths and preserves cellular structures. we tested the technique in three helminths: echinostoma paraensei, cruzia tentaculata, and hassalstrongylus epsilon. the results show that this t ...201324148995
aerobic to anaerobic transition in biomphalaria glabrata (say, 1818) infected with different miracidial doses of echinostoma paraensei (lie and basch, 1967) by high-performance liquid chromatography.the glucose content in the hemolymph and glycogen content in the digestive gland-gonad complex (dgg) and cephalopedal mass of biomphalaria glabrata exposed to different parasite doses (5 and 50 miracidia) of echinostoma paraensei as well as the activity of lactate dehydrogenase were evaluated. hplc (high-performance liquid chromatography) analyses were also performed to determine the concentrations of four organic acids (oxalic, succinic, pyruvic and lactic) present in the hemolymph of infected ...201323376444
biochemical and histopathological alterations in biomphalaria glabrata due to co-infection by angiostrongylus cantonensis and echinostoma paraensei.the effect of concurrent infection by echinostoma paraensei and angiostrongylus cantonensis on the activity of the enzymes alanine aminotransferase (alt) and aspartate aminotransferase (ast) and the concentration of total proteins, uric acid and urea in the hemolymph of biomphalaria glabrata were investigated. additionally, histopathological studies were conducted to better understand the dynamics of ontogenic development of both helminths in the host and the possible biochemical effects. co-inf ...201424513030
effect of the fungus pochonia chlamydosporia on echinostoma paraensei (trematoda: echinostomatidae).echinostoma paraensei is a trematode of the genus echinostoma that causes echinostomiasis in humans. the objectives of this study were to: evaluate the ovicidal activity of the nematophagous fungus pochonia chlamydosporia (vc1 and vc4) on a solid medium 2% water-agar (2% wa) against e. paraensei eggs (assay a); evaluate ovicidal effect (destruction of eggs) of the isolate vc4 in supplemented culture media (assay b); and evaluate the ovicidal ability of the crude extract (vc4) on e. paraensei egg ...201425046695
insights about echinostomiasis by paleomolecular diagnosis.echinostomiasis is a zoonosis caused by intestinal trematodes and transmitted by the ingestion of mollusks, crustaceans, fish, amphibians, and reptiles, either raw or poorly cooked. today human infection is endemic in southeast asia and the far east, but has been reported more recently in other regions of the world. interestingly eggs identified as echinostoma sp. were found in coprolites from a mummified body human in brazil, dated 560 ± 40 bp (before present). however, the specific diagnosis b ...201424780138
the role of fibrinogen-related proteins in the gastropod immune response.fibrinogen-related proteins or freps constitute a large family of molecules, defined by the presence of a fibrinogen-related domain (fred). these molecules are found in all animals and are diverse in both form and function. here, we review the current understanding of gastropod freps, which are characterized by the presence of a fibrinogen domain connected to one or two immunoglobulin superfamily domains by way of a short interceding region. we present a historical perspective on the discovery o ...201525765166
evaluation of the mitochondrial system in the gonad-digestive gland complex of biomphalaria glabrata (mollusca, gastropoda) after infection by echinostoma paraensei (trematoda, echinostomatidae).the effect of infection by echinostoma paraensei on the mitochondrial physiology of biomphalaria glabrata was investigated after exposure to 50 miracidia. the snails were dissected one, two, three and four weeks after infection for collection and mechanical permeabilization of the gonad-digestive gland (dgg) complex. the results obtained indicate that prepatent infection by this echinostomatid fluke significantly suppresses the phosphorylation state (respiratory state 3) and basal oxygen consump ...201627079167
ultrastructural and cytochemical characterization of t1 and t2 secretory bodies from the tegument of echinostoma paraensei.trematodes are lined by a syncytial layer that is named the tegument and contains small mitochondria and two different kinds of secretory inclusions. the structure and size of these bodies differs among genera and species. in a previous study, we observed many secretory bodies in the tegument of echinostoma paraensei and named these bodies the t1 and t2 secretory bodies. no previous studies analyzed the secretory bodies of trematodes from the genus echinostoma. thus, the aim of this work was to ...201626451647
in vivo and in vitro effects of the herbicide roundup(®) on developmental stages of the trematode echinostoma paraensei.the exposure of wildlife and humans to toxic residues of roundup(®) through agricultural practices or the food chain has been reported since the herbicide was found contaminating rivers. glyphosate, n-(phosphonomethyl)glycine acid, is a nonselective post-emergent herbicide and is formulated as an isopropylamine salt with the surfactant taloamine polyethoxylate (poea) representing the commercial formulation of roundup(®). there is little knowledge about the effects of the herbicide on helminth pa ...201627373431
light and scanning electron microscopy study of in vitro effects of artesunate in newly excysted metacercariae of echinostoma paraensei (trematoda: digenea).chemotherapy of food-borne trematodes relies on two drugs, praziquantel and tricabendazole, and there is growing interest in finding alternative therapies. plant oil extracts have long been used in traditional chinese medicine as sources of bioactive compounds with antiparasitic activity. species of the genus echinostoma are used as good models to test effective compounds against food-borne trematodes. this study evaluated the anthelmintic activity of crude artesunate extracts in vitro on newly ...201728131660
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