Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| search for antifungal, molluscicidal and larvicidal compounds from african medicinal plants. | african medicinal plants provide a rich source of biologically-active natural products. by the use of simple bioassays in conjunction with an approach involving bioactivity guided fractionation, it is possible to isolate novel compounds with interesting properties. several hundred plant extracts have been submitted to different screens, including bioautography on tlc plates with the fungi cladosporium cucumerinum and candida albicans. among the other test systems are a bioassay for molluscicidal ... | 1993 | 8510471 |
| [urban focus of schistosomiasis in a metropolitan area in a southeastern region of brazil]. | urban focus of schistosomiasis in an urban area of south-eastern, brazil. an active, urban focus of schistosomiasis in belo horizonte, mg, brazil is described. it is located in the "julien rien" park, a leisure area of 48,500 m2 created by the local administration in 1980 on the south side of city. snail captures were made over 10 years (1983-1992) resulting in the collection of 3,361 biomphalaria glabrata, ranging from 6.4 to 12.8 mm in diameter (mean = 9.3); 23 (0.7%) of these were found to be ... | 1993 | 8115836 |
| the introduction of melanoides tuberculata (mollusca: thiaridae) to the island of saint lucia (west indies) and its role in the decline of biomphalaria glabrata, the snail intermediate host of schistosoma mansoni. | a malacological survey was carried out in may 1992 in the whole hydrographic system of saint lucia 11 years after the end of a biological control programme to eliminate biomphalaria glabrata, the snail intermediate host of schistosoma mansoni. a competitor snail, melanoides tuberculata, was introduced to saint lucia in 1978 and field experiments in several habitats were conducted by prentice between 1978 and 1986. at the present time m. tuberculata is the most common freshwater snail in saint lu ... | 1993 | 8103624 |
| [molluscacidal activity of spiro-alpha-methylene-gamma-butyrolactone]. | the alpha-methylene-gamma-butyrolactones 1-28 were tested in vitro for molluscicidal activity against biomphalaria glabrata. the racemic compound 25 shows the best activity. the synthesis was carried out by modified reformatzky reaction of the corresponding carbonyl compounds and bromomethylacrylic acid ethyl ester. 7-10, 17 and 22-27 have been synthesized for the first time. | 1993 | 8122964 |
| partial purification of an endoglucanase from biomphalaria glabrata. | previous studies have shown that biomphalaria glabrata contains a complete cellulolytic system which includes an endoglucanase, an exoglucanase and a beta-glucosidase. in the present report, a scheme for the purification of the endoglucanase from this invertebrate is proposed. two major problems were encountered during the study: 1) the presence of a green-brownish pigment, which could not be eliminated by thermal shock or ammonium sulfate precipitation and 2) relative instability of enzymatic a ... | 1994 | 7549974 |
| [comparative breeding of helisoma duryi and biomphalaria glabrata in laboratory (mollusca, planorbidae)]. | 1994 | 263671 | |
| surface membrane polypeptides associated with hemocytes from schistosoma mansoni-susceptible and -resistant strains of biomphalaria glabrata (gastropoda). | previous studies have shown that hemocytes from inbred susceptible and resistant strains of the snail, biomphalaria glabrata, differentially react to primary sporocysts of the blood fluke, schistosoma mansoni. it has been hypothesized that this differential reactivity may be due to differences in the expression of hemocyte surface determinants serving as parasite recognition and/or hemocyte activating factors. in order to begin addressing this hypothesis the hemodynamics and surface polypeptides ... | 1994 | 8106743 |
| 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, ... | 1994 | 8152851 |
| high performance thin-layer chromatographic analysis of sugars in biomphalaria glabrata (gastropoda) infected with echinostoma caproni (trematoda). | high performance thin-layer chromatographic analysis was done on the hemolymph and digestive gland-gonad complex (dgg) of biomphalaria glabrata snails experimentally infected with the intramolluscan stages of echinostoma caproni. the major sugars detected in both the dgg and hemolymph of infected and uninfected snails were glucose and trehalose. quantitative analysis by scanning densitometry showed a significant reduction in glucose in both the hemolymph and dgg of infected snails at 4, 6, and 8 ... | 1994 | 8158483 |
| hirudinicidal activities of some natural molluscicides used in schistosomiasis control. | experiments were conducted with (molluscicides) aridanin isolated from tetrapleura tetraptera, aridan, an extract from t. tetraptera, endod, an extract from phytolacca dodecandra and niclosamide on non-target aquatic organisms such as leech, hydra, tadpoles, anopheline mosquito larvae and brine shrimps and compared with their toxicity to the target snail. biomphalaria glabrata. aridanin, aridan, endod, and niclosamide produced rapid knockdown effects on b. glabrata at 0.04, 1.00, 30.00, and 40.0 ... | 1994 | 8170154 |
| transfer of resistance to schistosoma mansoni in biomphalaria glabrata by allografts of amoebocyte-producing organ. | allografts of amoebocyte-producing organ (apo) were implanted heterotopically into the schistosome-susceptible nih albino stock of biomphalaria glabrata from either 13-16-r1 (a schistosome-resistant stock) or nih albino donors. at 3, 7-8, 14-15, 21, 28-33, or 47-71 days postimplantation (pi), allograft recipients were exposed to 50 miracidia each of schistosoma mansoni and subsequently monitored for development of sporocysts and cercariae. relative to untampered snails and recipients of nih albi ... | 1994 | 8195947 |
| characterization of immunoreactive tnf alpha molecules in the gastropod biomphalaria glabrata. | in recent years, several studies have demonstrated the existence of cytokine-like molecules in invertebrates, therefore suggesting that cytokines may have been conserved throughout evolution. in this study, we investigated the presence of immunoreactive tnf alpha (ir tnf alpha) in the gastropod mollusc biomphalaria glabrata, the specific intermediate host for the trematode schistosoma mansoni. immunocytochemical study indicated the presence of ir tnf alpha in mollusc hemocytes corresponding to a ... | 1994 | 8001700 |
| interleukin 1 activity in haemolymph from strains of the snail biomphalaria glabrata varying in susceptibility to the human blood fluke, schistosoma mansoni: presence, differential expression, and biological function. | cytokines control many of the steps in the complex pathways of immune and inflammatory responses in mammals. recent reports also indicate that some invertebrates may produce cytokines such as interleukin 1 (il-1). certain strains of the snail, biomphalaria glabrata (intermediate host for the human blood fluke, schistosoma mansoni), possess a soluble plasma factor that stimulates the haemocyte-mediated killing of larval schistosomes, making them resistant to infection. in this study, we have soug ... | 1994 | 8003629 |
| parthenogenesis in the genus schistosoma: electrophoretic evidence for this reproduction system in s. japonicum and s. mansoni. | mixed infections with schistosoma japonicum and s. mansoni were carried out in mice. s. japonicum females paired with s. mansoni males developed normally and produced numerous viable eggs; very little sperm was found in the female genital tract. the eggs yielded many miracidia infective to oncomelania hupensis, the host of s. japonicum. cercariae arising from miracidia developed into male worms with an electrophoretic pattern of malate dehydrogenase (mdh) corresponding only to the maternal speci ... | 1994 | 8036230 |
| schistosoma mansoni: modulation of hemocyte surface polypeptides detected in individual snails, biomphalaria glabrata, following larval exposure. | as an approach to better understand the molecular mechanisms underlying the differential cellular response to larval schistosoma mansoni observed in biomphalaria glabrata, we have analyzed hemocyte membrane-associated polypeptides from inbred susceptible and resistant strains of b. glabrata. a combination of techniques involving biotin-labeling of cell surface-exposed polypeptides and a highly sensitive chemiluminescent detection technique has allowed the identification of major polypeptides exp ... | 1994 | 8050520 |
| schistosoma mansoni: relationship between low fecundity and reduced susceptibility to parasite infection in the snail biomphalaria glabrata. | biomphalaria glabrata snails which were not susceptible as juveniles to infection by schistosoma mansoni were selectively bred (by self-fertilization) from the highly susceptible nmri laboratory snail stock. the susceptibility rate among juvenile snails derived from interbreeding nmri parents was initially 85-95%, but after several generations of selection, less than 5% of exposed snails became infected by the parasite. selection for low susceptibility also resulted in a large proportion of snai ... | 1994 | 8050522 |
| 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 ... | 1994 | 8064176 |
| schistosomicidal activities of lymnaea stagnalis haemocytes: the role of oxygen radicals. | macrophage-like defence cells (haemocytes) of the pond snail lymnaea stagnalis mediate cytotoxicity through reactive oxygen intermediates (rois). this activity is nadph-oxidase dependent, as in mammalian phagocytes during the respiratory burst. in this study, mother sporocysts of schistosomes, the compatible trichobilharzia ocellata and the incompatible schistosoma mansoni evoke in vitro roi activities (detected by luminol dependent chemiluminescence, ldcl) from l. stagnalis haemocytes. s. manso ... | 1994 | 7800416 |
| biomphalaria glabrata: extensive genetic variation in brazilian isolates revealed by random amplified polymorphic dna analysis. | to examine the extent of genetic variation in biomphalaria glabrata, the intermediate host of schistosoma mansoni, specimens from seven brazilian isolates were studied. regions of genomic dna were amplified using short, arbitrarily selected oligonucleotide primers under low-stringency conditions (random amplified polymorphic dnas--rapds) and analyzed by polyacrylamide gel electrophoresis followed by silver staining. the rapd profiles of snails of the same isolate were relatively homogeneous, wit ... | 1994 | 7914497 |
| interspecific stimulation of parthenogenesis in schistosoma intercalatum and s. mansoni. | experimental studies of mating behaviour of schistosoma intercalatum and schistosoma mansoni in mixed infections in mice showed that in simultaneous infections, without the possibility of choice of mate, heterologous pairing occurs readily. the paired females reach sexual maturity, are inseminated and lay parthenogenetic eggs. miracidia originating from the s. mansoni male x s. intercalatum female are non infective to either biomphalaria glabrata or bulinus forskalii, whereas those from the reve ... | 1994 | 7930460 |
| 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 ... | 1994 | 7931907 |
| antibacterial and molluscicidal phenolic acids from spondias mombin. | spondias mombin l. (anacardiaceae), used in traditional medicine because of its antimicrobial properties, was found to contain a series of 6-alkenyl-salicylic acids. they were isolated from the ethanolic extract of leaves and stems of spondias mombin by a combination of chromatographic methods. their structure was determined by nmr and ms techniques as (17:3), (17:2) and (17:1) pelandjuaic acid [or 6-(8'z,11'z,14'z-heptadecatrienyl)-salicylic acid, 6-(8'z,11'z-heptadecadienyl)-salicylic acid, an ... | 1994 | 7997478 |
| fermentation and toxin studies of the molluscicidal strains of bacillus brevis. | strain ss86-4 was one of 40 bacillus brevis strains shown to be molluscicidal to the schistosomiasis snail vector biomphalaria glabrata. when grown in mb4 medium in 2-l fermentors, ss86-4 was molluscicidal only if fructose or phenylalanine was present in the medium. this is reminiscent of secondary fermentation factor effects, in this case an antioxidant effect. in vivo proteases also were capable of reducing molluscicidal activity. the molluscicidal toxin has an lc50 of 1 microgram toxin protei ... | 1994 | 7764671 |
| molluscicidal saponins from a zimbabwean strain of phytolacca dodecandra. | three new monodesmosidic saponins, all glycosides of 2 beta-hydroxyoleanolic acid, were isolated from an aqueous extract of a zimbabwean strain of phytolacca dodecandra. their structures were, mainly by spectroscopic methods (lsims, 1h nmr, cosy, noesy, tocsy, j-resolved 1h nmr, 13c nmr, hetcor), established as 3-o-[2',4'-di-o-(beta-d-glucopyranosyl)-beta-d-glucopyranosyl]2 beta-hydroxyoleanolic acid, 3-o-[o-alpha-l-rhamnopyranosyl-(1-->2)-o-[beta-d-galactopyranosyl- (1-->3)]-beta-d-glucopyranos ... | 1994 | 7765003 |
| studies on host-parasite relationship between the puerto rican strain of schistosoma mansoni and biomphalaria snails. | immunoelectrophoretic studies on common antigenicities were carried out by using rabbits sera immunized with the puerto rican strain of schistosoma mansoni adult worms or eggs and antigens of several adult biomphalaria snails and vice versa. as the result, s. mansoni adult worm extracts produced 8 bands both with extracts of biomphalaria glabrata pigmentation and b. glabrata pigmentado, 3 to 4 bands with those of b. glabrata albino and 1 to 2 bands with those of b. straminea. on the other hand, ... | 1994 | 7777917 |
| invertebrate host-parasite relationships: convergent evolution of a tropomyosin epitope between schistosoma sp., fasciola hepatica, and certain pulmonate snails. | monoclonal antibodies (mab) directed against schistosoma mansoni tropomyosin isoform, smtm (xu et al. experimental parasitology 69, 373-392, 1989), were used to test for cross-reactivity with biomphalaria glabrata antigens. one mab (1f10) recognized antigens of 39, 41, and 80 kda in a snail head/foot antigen preparation but not a hepatopancreas antigen preparation. another mab (1c1) cross-reacted with a 39-kda antigen in the head/foot extract but not in the hepatopancreas extract. epitope mappin ... | 1994 | 7512930 |
| [susceptibility of biomphalaria tenagophila and biomphalaria glabrata from a same region to 2 schistosoma mansoni strains]. | b. tenagophila snails from ouro branco, mg, showed positivity for s. mansoni, with infection rates of 5%, 10%, (sj strain), and 1% (le strain) using a pool of miracidia. the mollusks were found to be susceptive from the 3rd generation reared in laboratory onwards. the b. tenagophila (ob, mg) when individually exposed to 10 miracidia, showed infection rate of 2% for le strain. b. glabrata snails from gagé, mg, showed a positivity rate of 58% for s. mansoni (le strain), under experimental conditio ... | 1994 | 7569607 |
| production of schistosoma mansoni cercariae by biomphalaria glabrata from a focus in belo horizonte, minas gerais. | the snail density, levels of infection and the monthly production of schistosoma mansoni cercariae by biomphalaria glabrata were determined in a focus of barreiro de baixo (belo horizonte, mg, brazil). during a period of 38 months (1984 to 1987) 5,366 snails were collected of which 324 (6.03%) were infected with s. mansoni. the total number of cercariae shed was 5,667,312. each snail shed an average of 17,422 cercariae during the time that it was under study in the laboratory. the greatest longe ... | 1994 | 7569620 |
| distribution of schistosome genetic diversity within molluscan intermediate hosts. | naturally infected biomphalaria glabrata snails were collected at two sites near belo horizonte, brazil, and schistosoma mansoni cercariae isolated from single snails were used to infect individual mice. genetic comparison of single worm dna was accomplished by hybridization of southern blots to a polymorphic repetitive dna element. genetic profiles of parasite individuals revealed a diverse array of parasite genotypes in naturally infected intermediate hosts. the observed distribution of schist ... | 1995 | 7675537 |
| molluscicidal saponins from catunaregam nilotica. | two new saponins were isolated from the fruits of catunaregam nilotica stapf, syn. lachnosiphonium nilotica; randia nilotica; xeromphis nilotica. their structures were determined mainly by spectroscopic methods as 3- o-[o-alpha-l-rhamnopyranosyl-(1-->3)-o-[o-beta-d-glucopyranosyl-(1 -->3)]- beta-d-glucopyranosyl]oleanolic acid and 28-o-beta-d- glucopyranosyl-3-o-[o-alpha-l-rhamnopyranosyl-(1-->3)-o[o-beta-d- glucopyranosyl]-beta-d-glycopyranosyl]oleanolate. the monodesmosidic saponin is a potent ... | 1995 | 7786492 |
| hemocytes of schistosome-resistant and -susceptible biomphalaria glabrata recognize different antigens on the surface of schistosoma mansoni sporocysts. | a cytoadherence assay was used to determine whether antibodies to plasma and hemocyte components of schistosoma mansoni-susceptible (m-line) and -resistant (10-r2, 13-16-r1) strains of biomphalaria glabrata affected attachment of hemocytes to chemically fixed schistosome sporocysts differentially. experiments used purified, intact igg and purified fab fragments of each antibody. indirect fluorescent antibody tests confirmed that the intact purified igg to plasma and hemocytes from the 3 strains ... | 1995 | 7707192 |
| comparative infectivity and survival of first-stage larvae of angiostrongylus cantonensis and angiostrongylus malaysiensis. | angiostrongylus malaysiensis was isolated from wild rats rattus norvegicus in a seaport area of kitakyushu city, kyushu, japan in 1990. the infectivity and survival capacities of first-stage larvae of a. malaysiensis and angiostrongylus cantonensis were compared under various conditions. infectivity of first-stage larvae of the former in biomphalaria glabrata was much lower than that of the latter. in an exposure at various phs, and with various proteases and tissue homogenates of b. glabrata, t ... | 1995 | 7707198 |
| spatial distribution patterns of the sporocyst infrapopulation of schistosoma mansoni within its mollusc host (biomphalaria glabrata): an unusual phenotype of aggregation. | a study carried out on the intramolluscan development of the larval stages of schistosoma mansoni from venezuela in its intermediate host biomphalaria glabrata shows the existence of 2 patterns for the spatial distribution of daughter sporocysts within the digestive gland of the snail. besides the normal pattern, which is a random distribution of daughter sporocysts within the gland, 11% of the infected snails harbored an infection phenotype with daughter sporocysts strongly aggregated in only t ... | 1995 | 7707215 |
| schistosoma mansoni: interleukin-1 increases phagocytosis and superoxide production by hemocytes and decreases output of cercariae in schistosome-susceptible biomphalaria glabrata. | decreases in the number of schistosoma mansoni cercariae released from susceptible m-line biomphalaria glabrata were detected following injection with the recombinant human cytokine, interleukin-1. no differences in either the time post-exposure at which shedding began or the percentage of snails shedding cercariae were detected between interleukin-1 injected, heat-inactivated interleukin-1 injected, or sham injected controls. however, sham injected and heat-inactivated interleukin-1 injected sn ... | 1995 | 7821403 |
| [relationship between the pathogenicity of schistosoma mansoni in mice and the susceptibility of the vector mollusk. iii. mortality, body and viscera weight]. | the relationship between the development of hepatomegaly, splenomegaly, body weight and mortality rate and the degree of susceptibility of biomphalaria glabrata and b. tenagophila at which infective cercariae developed was studied. the study utilized swiss mice, spf, as definitive hosts and populations of snails genetically selected for character susceptibility as intermediate hosts. low body weight and smaller viscera were observed in infected mice with cercariae originating from snails that sh ... | 1995 | 8729275 |
| biological screening of traditional medicinal plants from papua new guinea. | based on ethnopharmacological literature, 17 species of medicinal plants used in the traditional medicine in papua new guinea were collected. extracts of different polarities were tested in a preliminary biological screening for their antimicrobial (escherichia coli, bacillus subtilis, micrococcus luteus and penicillium oxalicum) and molluscicidal activity against biomphalaria glabrata as well as for their toxicity to brine shrimp. the pretreated plant extracts were also investigated for their a ... | 1995 | 8824740 |
| development of schistosoma mansoni in biomphalaria tenagophila, biomphalaria straminea and biomphalaria glabrata. | a comparative study of the development of schistosoma mansoni during the intra-molluscan phase was made by means of histological sections of biomphalaria tenagophila, b. straminea and b. glabrata from brazil. two hundred snails of each species were individually exposed to 50 miracidia of the s. mansoni, al line. no larvae were observed in the snails fixed 72 h after exposure. in specimens shedding cercariae, 31 days after exposure tissue reactions encapsulating the larvae were seen in b. tenagop ... | 1995 | 8525264 |
| effect of niclosamide (bayluscide wp 70), anacardium occidentale hexane extract and euphorbia splendens latex on behavior of biomphalaria glabrata (say, 1818), under laboratory conditions. | the repellent effect of the molluscicides niclosamide (bayluscide wp 70), anacardium occidentale and the latex of euphorbia splendens on biomphalaria glabrata was observed through the investigation of the occurrence of escape behavior among molluscs that were exposed to dosages lower than the ld 50. the total number of individuals out of water among the surviving snails in the control group provided a "natural escape index". the comparison between this total and the total number of surviving sna ... | 1995 | 8531656 |
| dna polymorphism of schistosomes and their snail hosts. | analysis of the genomes of schistosomes and one of their intermediate hosts, biomphalaria glabrata, using random amplified polymorphic dna (rapd) demonstrated that intraspecific genetic polymorphism in the parasite is limited but in the snail is highly pronounced. this suggests an important role for the snail in the determination of the epidemiology of the disease. in addition to their intraspecific stability, schistosome derived rapds exhibit a high level of interspecific polymorphism and are t ... | 1995 | 8531659 |
| a method for immunoisolation of sporocysts of schistosoma mansoni in nonsusceptible snails. | a technique is described for immunoisolation of sporocysts of schistosoma mansoni in nonsusceptible biomphalaria glabrata by microencapsulation in agarose. based on histological evidence, all 11 microencapsulated sporocysts implanted into 3 schistosome-resistant 13-16-r1 snails were alive at 72 hr postimplantation, although in a developmentally retarded condition. however, among 146 sporocysts derived from miracidia that had penetrated 5 snails, 96% were dead by 72 hr. these results suggest that ... | 1995 | 8544049 |
| schistosoma mansoni: changes in the albumen gland of biomphalaria glabrata snails selected for nonsusceptibility to the parasite. | the lac-line strain of the snail biomphalaria glabrata has very low susceptibility to the parasite schistosoma mansoni and a very low reproductive potential. upon examination of the reproductive tract of these snails, light and electron microscopy revealed obvious abnormalities in the albumen gland. secretory cells that are normally cuboidal in susceptible nmri (f0) snails were squamous in lac-line snails. these lac-line cells contained small secretory granules and negligible rough endoplasmic r ... | 1995 | 8544062 |
| longitudinal study of circadian rhythms in the cercarial emergence of schistosoma mansoni from biomphalaria glabrata. | 1995 | 8551950 | |
| cercarial emergence of schistosoma mansoni from biomphalaria glabrata and biomphalaria straminea. | 1995 | 8569474 | |
| the plasma proteins of biomphalaria glabrata in the presence and absence of schistosoma mansoni. | snail plasma serves as both a sink for metabolites and a source of nutrients for parasites developing within their intermediate hosts. it also contains molecules involved in immunological events like non-self recognition, phagocytosis and encapsulation. in this study we present improved protocols for the separation and partial characterization of plasma proteins of schistosome-susceptible and resistant strains of biomphalaria glabrata. within each strain, the plasma of snails 12, 24, 48 and 72 h ... | 1995 | 8595817 |
| influence of temperature on development of schistosoma mansoni female cercariae in biomphalaria glabrata. | in these experiments the ratio of male to female s. mansoni larvae in b. glabrata from belo horizonte and ribeirão das neves minas gerais, brazil, either reared in laboratory or collected in the field, varied from 1:1 to 1:1.3 or 1.4:1. cercariae of le strain of schistosoma mansoni, shed by 39 snails maintained at 25 +/- 0.5 degrees c were used to infect mice on a weekly basis. subsequent perfusion resulted in 76.6% male and 23.4% female worms. the cercariae produced by 32 infected snails mainta ... | 1995 | 8599060 |
| production of schistosoma mansoni daughter sporocysts from mother sporocysts maintained in synxenic culture with biomphalaria glabrata embryonic (bge) cells. | in vitro production of schistosoma mansoni daughter sporocysts (ds) from miracidium-derived mother sporocysts (ms) was achieved by synxenic larval cultivation with cells of the biomphalaria glabrata embryonic (bge) cell line. the in vitro growth and viability of ms cocultured with bge cells or in bge cell-conditioned medium were significantly extended beyond that of larvae cultured in fresh medium alone. however, complete ds development and emergence from ms were achieved only in the presence of ... | 1995 | 7472861 |
| killing of schistosoma mansoni sporocysts in biomphalaria glabrata implanted with amoebocyte-producing organ allografts from resistant snails. | schistosome-susceptible national institutes of health (nih) albino biomphalaria glabrata were implanted with the amoebocyte-producing organ (apo) from 4 types of donors: (1) exposed-resistant (er), i.e., schistosome-resistant 13-16-r1 snails that had been exposed to miracidia of schistosoma mansoni 30 or more days previously in order to verify their resistance, (2) exposed-susceptible (es), i.e., nih albino snails that had been similarly exposed to miracidia, (3) unexposed-resistant (ur), and (4 ... | 1995 | 7472893 |
| schistosoma mansoni: excretory-secretory polypeptides exhibit selective binding to plasma components of the snail biomphalaria glabrata. | previous studies have shown that schistosoma mansoni excretory-secretory polypeptides (esp) inhibit various internal defense functions of hemocytes from biomphalaria glabrata and that plasma also may exert a modulatory effect on hemocyte activity. to better understand how plasma may influence hemocyte-schistosome interactions in inbred strains of snails, biotinylated esp (b-esp) were used as probes to identify esp-reactive plasma components and partially characterize the nature of their binding ... | 1995 | 7498426 |
| activity of the molluscicidal plant millettia thonningii (leguminosae) toward biomphalaria glabrata eggs. | a dichloromethane extract of the seeds of the molluscicidal west african legume millettia thonningii was tested for ovicidal activity toward biomphalaria glabrata egg masses. the extract was found to be highly ovicidal at concentrations as low as 5 mg/l. embryonic development of the snails in egg masses was monitored using photomicrographs from which embryonic diameters were estimated. such measurements revealed that ovicidal effects were developmentally stage specific and normally induced a cur ... | 1995 | 7472894 |
| effects of diet on the lipid composition of the digestive gland-gonad complex of biomphalaria glabrata (gastropoda) infected with larval echinostoma caproni (trematoda). | this study examined the effects of a larval echinostoma caproni infection on the neutral lipid composition of the digestive gland-gonad complex (dgg) of biomphalaria glabrata snails fed hen's egg yolk supplemented with lettuce (y-l) or lettuce supplemented with tetramin (l-t). snails were experimentally infected with the miracidial stage of this echinostome, and their dggs containing daughter rediae were analyzed for neutral lipids five weeks post-infection by qualitative and quantitative thin-l ... | 1995 | 7749624 |
| experimental infection of juvenile biomphalaria glabrata with cercariae of echinostoma trivolvis. | infectivity studies were done on laboratory-reared biomphalaria glabrata juvenile (neonatal) snails exposed to cercariae of echinostoma trivolvis. of the 40 snails, 0.7-1.0 mm in shell diameter, which were exposed to a total of 1,000 cercariae for 24 hr, all were infected with 1-29 viable encysted metacercariae per snail. biomphalaria glabrata, 1-2 mm in shell diameter, were used to determine the effects of an infectious dose of 25 cercariae/juvenile on subsequent snail survival. the median surv ... | 1995 | 7707214 |
| biosynthesis of the storage polysaccharide from the snail biomphalaria glabrata, identification and specificity of a branching beta 1-->6 galactosyltransferase. | adult snails synthesize in their albumen glands a storage polysaccharide called galactan which is utilized by the developing embryos. with [6-3h]-uridine 5'diphosphogalactose the incorporation of labelled d-galactose into the polysaccharide can be traced in freshly removed glands maintained in a bathing buffer. after centrifugation of homogenized glands, galactosyltransferase activity is only found in the insoluble fraction. chaps extracts of this material retain almost all of their activity and ... | 1995 | 7560306 |
| egg laying in vitro of echinostoma caproni (trematoda) in nutritive and nonnutritive media. | egg laying in vitro was studied in echinostoma caproni adults placed in 10 ml of nutritive or nonnutritive media for 48 h in petri-dish cultures maintained at 37 degrees c in an atmosphere containing 7.6% co2. maximal egg laying occurred within 24 h in the defined medium rpmi 1640. egg laying was significantly greater in this medium than in mccoy's or locke's solution. eggs released into the rpmi medium were capable of producing miracidia that were infective to biomphalaria glabrata snails. frie ... | 1996 | 8738289 |
| phenoloxidase activity in the reproductive system and egg masses of the pulmonate gastropod, biomphalaria glabrata. | phenoloxidase (po) activity in the albumen gland (ag) and egg masses (em) of biomphalaria glabrata was assessed using high-performance liquid chromatography combined with electrochemical detection and colorimetric techniques. both ag and em extracts catalyzed the hydroxylation of l-tyrosine (monophenol oxidase activity, mpo) and oxidation of l-dopa (diphenol oxidase activity, dpo). however, no po activity was found in the ovotestis. both mpo and dpo activities in ag and em were significantly inh ... | 1996 | 8840512 |
| studies on the sacculant portion of the kidney of biomphalaria glabrata say (1818) as a haemopoietic organ. | the term immunity signifies all those properties of the host which confer resistance to a specific infectious agent. this resistance may be of all degrees ranging from complete to incomplete susceptibility. the defensive functions is performed by various cellular and humoral components which interact with each other producing a co-ordinated immune response directed towards eliminating the pathogen or minimizing its danger. snails as other members of the animal kingdom have their own immune syste ... | 1996 | 8754649 |
| the effects of extracts from tetrapleura tetraptera (taub.) and bayluscide on cells and tissue structures of biomphalaria glabrata (say). | subchronic experiments were conducted with low concentrations of saponins from tetrapleura tetraptera and bayluscide to study the ultrastructural effects of these molluscicides on biomphalaria glabrata. the ratio of the digestive cells to the crypt cells was inverted in molluscicide treated snails which showed an increase in the number of secretory cells and a decrease in the number of digestive cells. in the snail foot connective tissues, dose-dependent autolytic areas were observed. the major ... | 1996 | 8866731 |
| dna transfer in a biomphalaria glabrata embryonic cell line by dotap lipofection. | 1996 | 8832743 | |
| development, hatching, and infectivity of echinostoma caproni (trematoda) eggs, and histologic and histochemical observations on the miracidia. | light microscopy studies were done on the eggs and miracidia of the intestinal trematode echinostoma caproni. eggs were obtained by homogenizing adult worms derived from icr mice in artificial spring water (asw). to study egg development and to obtain miracidia, eggs were incubated in asw in either a light or a dark environment for 10 days at 28 degrees c. egg development was characterized and staged at 2-day intervals from day 0 to day 10 postembryonation. no significant difference in developme ... | 1996 | 8825208 |
| use of rapd-pcr to differentiate genetically defined lines of an intermediate host of schistosoma mansoni, biomphalaria glabrata. | the genetic differentiation among several laboratory-maintained pedigree snail lines of biomphalaria glabrata (with different susceptibility phenotypes to schistosoma mansoni infection) was assessed with the random amplified polymorphic dna method. out of the 20 primers tested, 2 (opa-01 and opa-06) gave reproducible markers with either individual or bulked dna samples from resistant (bs-90, 10-r2, lac-line) and susceptible (m-line) snails. arbitrary primer, opa-01, amplification of bs-90 dna id ... | 1996 | 8604090 |
| killing of schistosoma mansoni sporocysts by biomphalaria glabrata hemolymph in vitro: alteration of hemocyte behavior after poly-l-lysine treatment of plastic, and the kinetics of killing by different host strains. | behavior of hemocytes of the gastropod mollusc biomphalaria glabrata was markedly changed on plastic by treatment of the substrate with 0.1 mg/ml poly-l-lysine compared to behavior on untreated plastic. on lysine, the cells showed minimal spreading, moved significantly faster, and formed aggregates. cell-mediated cytotoxicity (cmc) assays were set up on the modified and untreated substrates to compare the killing capacities of b. glabrata hemocytes against schistosoma mansoni sporocysts. hemolym ... | 1996 | 8604109 |
| inhibition of cysteine proteinase from schistosoma mansoni larvae by alpha-macroglobulin from the plasma of biomphalaria glabrata. | the hemolymph of biomphalaria glabrata, a molluscan host of schistosoma mansoni, contains an alpha-macroglobulin proteinase inhibitor (alpham). in this study we have demonstrated that this host molecule inhibits a cysteine proteinase produced by larval s. mansoni. inhibition by alpham involves conformational changes through proteolytic cleavage by the proteinase, thus the enzyme must be active for interactions to occur. a specific cysteine proteinase inhibitor (e64) was used to block the interac ... | 1996 | 8604113 |
| male reproductive success of schistosoma mansoni-infected biomphalaria glabrata snails. | infection of biomphalaria glabrata by schistosoma mansoni results in a dramatic reduction in the snail's ability to produce eggs. we studied the ability of such parasitically castrated snails to fertilize the eggs of uninfected snails. pigmented b. glabrata snails (13141 stock) were infected with s. mansoni miracidia and reared individually until they ceased laying eggs. these infected snails were then given the opportunity to mate with uninfected albino (nmri) snails. each of the infected snail ... | 1996 | 8636847 |
| purification and characterization of a tetrameric alpha-macroglobulin proteinase inhibitor from the gastropod mollusc biomphalaria glabrata. | the alpha-macroglobulin proteinase inhibitors (alpha ms) are a family of proteins with the unique ability to inhibit a broad spectrum of proteinases. whereas monomeric, dimeric and tetrameric alpha ms have been identified in vertebrates, all invertebrate alpha ms characterized so far have been dimeric. this paper reports the isolation and characterization of a tetrameric alpha m from the tropical planorbid snail biomphalaria glabrata. the sequence of 18 amino acids at the n-terminus indicates ho ... | 1996 | 8670168 |
| analysis of lectin- and snail plasma-binding glycopeptides associated with the tegumental surface of the primary sporocysts of schistosoma mansoni. | carbohydrates associated with the tegumental surface of schistosoma mansoni primary sporocyst may serve as potential receptors for mediating recognition by the internal defence system of the molluscan host, biomphalaria glabrata. therefore, a combination of sds-page and lectin probe analyses were carried out on biotin-labelled tegumental glycopeptides as a first step to defining the carbohydrates expressed at the sporocyst surface. the majority of surface polypeptides, ranging in relative molecu ... | 1996 | 8677136 |
| barbamide, a chlorinated metabolite with molluscicidal activity from the caribbean cyanobacterium lyngbya majuscula. | the lipid extract from a curaçao collection of the marine cyanobacterium lyngbya majuscula was toxic to the mollusc biomphalaria glabrata. subsequent bioassay-guided fractionation of this extract yielded a novel lipopeptide, barbamide, as the active compound (lc100 = 10 micrograms/ml). the structure of barbamide was determined by spectroscopic methods and was found to contain several unique structural features, including a trichloromethyl group and the methyl enol ether of a beta-keto amide. | 1996 | 8699186 |
| biomphalaria glabrata: a new threat for schistosomiasis transmission in egypt. | this is the first report on the infestation of irrigation and drainage systems at giza, qalyoubiya and kafr el shiekh governorates, with biomphalaria glabrata (the snail host of schistosoma mansoni in the new world). identification of this snail species was based on morphometry of the shell, shape of the radular lateral teeth and presence of the characteristic renal ridge. b. glabrata snails collected from natural water courses in egypt proved to be susceptible to a local strain of s. mansoni. t ... | 1996 | 8721240 |
| circadian pattern of cercarial emergence in schistosoma mansoni (platyhelminthes:digenea) from isolated biomphalaria glabrata. | the present work aimed to compare the acrophases (peak hours) of emergence of schistosoma mansoni cercariae among isolated individuals of the snail biomphalaria glabrata. laboratory stocks of melanic b. glabrata from the same biotope as the s. mansoni strain (belo horizonte, minas gerais) were used. twenty-two snails individually exposed to five miracidia were tested. chronobiological trials were performed outdoors after an acclimation period of at least a week. three groups of snails were teste ... | 1996 | 8877118 |
| identification of the first major allergen of a squid (todarodes pacificus). | in japan, squid is an important seafood, and some patients with food allergies are sensitive to squid. there has been no report, however, describing the major allergens of squid. | 1996 | 8939158 |
| schistosoma mansoni: use of a subtractive cloning strategy to search for rflps in parasite-resistant biomphalaria glabrata. | a subtractive cloning strategy has been applied for the identification of two cdna clones whose corresponding transcripts were elevated in schistosoma mansoni-resistant (bs-90) compared to susceptible (m-line) snails. clone pbs11 encoded a 1.9-kb transcript that was more elevated compared to a 500-bp transcript encoded by clone pbs12. consequently, more attention was focused on the molecular characterization of clone pbs11. results showed that the transcript encoded by this clone was expressed i ... | 1996 | 8948331 |
| urban schistosomiasis: morbidity, sociodemographic characteristics and water contact patterns predictive of infection. | schistosomiasis (schistosoma mansoni) is classically described as a rural disease that occurs in areas with poor sanitary conditions. this cross-sectional study was undertaken in a suburban area of a large industrialized city in brazil (belo horizonte), aiming at examining epidemiological characteristics of schistosomiasis in an urban setting. | 1996 | 9027538 |
| schistosoma mansoni: the sex ratios of worms in animals infected with cercariae from three species of biomphalaria. | the ratios of male to female worms of schistosoma mansoni were determined in mice infected with cercariae from le, sj and al strains shed by mollusc hosts of the parasite in brazil. the sex ratios of worms in the animals were similar with cercariae from biomphalaria glabrata and b. tenagophila varying from 1.1:1 to 1.6:1 with le and al strains and 1:1.1 with sj. in the animals infected with cercariae from b. straminea the ratio of male to female worms was similar to those obtained using cercaria ... | 1996 | 9071034 |
| schistosoma mansoni: the ultrastructure of larval morphogenesis in biomphalaria glabrata and of associated host-parasite interactions. | an electron microscopic study has been carried out to describe the transformation of the miracidium of s. mansoni into the mother sporocysts in the susceptible b. glabrata and the associated host-parasite interactions. the miracidium enters the snail host without morphological alterations. within 3 hr after entering, all the ciliary epidermal plates of the miracidium are discarded. a new tegument is quickly formed by 5 hr postinfection by the expansion of epidermal ridges. the rapid formation of ... | 1996 | 9086392 |
| phagocytosis of latex beads by biomphalaria glabrata hemocytes is modulated in a strain-specific manner by adsorbed plasma components. | circulating phagocytes of the mollusc biomphalaria glabrata help determine the fate of invading schistosoma mansoni larvae. in mediating cytotoxicity against this trematode parasite, phagocytic hemocytes may interact with unidentified plasma components. in this study, positively and negatively charged latex beads were coated with plasma for use in in vitro phagocytosis assays. hemocytes from s. mansoni-susceptible and -resistant strains of b. glabrata were tested for their ability to internalize ... | 1996 | 8738934 |
| biogenic monoamines in the freshwater snail, biomphalaria glabrata: influence of infection by the human blood fluke, schistosoma mansoni. | the biogenic monoamines, serotonin (5-ht), dopamine (da) and l-dopa were measured using high performance liquid chromatography with electrochemical detection (hplc-ed) in the extracts of the central nervous system (cns) and plasma of uninfected freshwater snails, biomphalaria glabrata, and in snails at 7, 14, 21 and 28 days postexposure (pe) to the miracidia of the human blood fluke, schistosoma mansoni. relative to age-matched uninfected snails, a general depression of biogenic amine levels was ... | 1996 | 8759145 |
| in vitro cultivation of angiostrongylus costaricensis eggs to first stage larvae in chemically defined medium. | angiostrongylus costaricensis eggs were successfully cultured to first stage larvae in a chemically defined medium. the most suitable medium for development was ham's f-12 among 7 chemically defined media and 10 serum supplemented media examined. the addition of serum to ham's f-12 did not provide any further benefits for egg development. when the eggs were cultured in this medium under 8% co2 in air, they developed and formed larvae inside the eggs 5 days later. thereafter, the eggs began to ha ... | 1996 | 8786217 |
| altered nutrition and assimilation of the snail host (biomphalaria glabrata) as a consequence of the parasitic spatial constraint (schistosoma mansoni). | 1996 | 9133164 | |
| [behavior of hemolymph amebocytes from planorbidae in the presence of schistosoma mansoni larvae parasitism, after inoculation of indian ink or fracture of the shell]. | the behavior of the hemolymph amebocytes of biomphalaria glabrata and biomphalaria tenagophila was studied by means of the infection by the schistosoma mansoni, using inoculation with indian ink and fracture of the shell. a differential count of the amebocytes in the hemolymph was made with special attention given to the types of cell found in each sample. histopathological evaluation of the molluscs exposed to the schistosoma mansoni miracidia and analyses of the amebocytes were made. correlati ... | 1996 | 9201894 |
| a low stringency polymerase chain reaction approach to the identification of biomphalaria glabrata and b. tenagophila, intermediate snail hosts of schistosoma mansoni in brazil. | the low stringency-polymerase chain reaction (ls-pcr) with a pair of specific primers for the amplification of the 18s rrna gene was evaluated as a means of differentiating between the two schistosoma mansoni intermediate host species in brazil: biomphalaria glabrata and b. tenagophila. individual snails obtained from different states of brazil were used and the amplification patterns obtained showed a high degree of genetic variability in these species. nevertheless, 4 and 3 clearly defined spe ... | 1996 | 9283656 |
| effect of 60co gamma radiation on biomphalaria glabrata (mollusca, gastropoda) embryos: mortality, malformation and hatching. | a study was carried out on the radiosensitivity of biomphalaria glabrata embryos submitted to doses of 5, 10, 15, 20 and 25 gy of 60co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. mortality, malformation and hatching were the parameters used to evaluate the damage induced by ionizing radiation. estimated ld50 values (15 days) showed that the cleavage stage (4.3 gy) was approximately four times more radiosensitive than the trochophore stage (17.0 gy). suscept ... | 1996 | 9181090 |
| detection of schistosoma mansoni in biomphalaria using nested pcr. | a nested polymerase chain reaction (pcr) protocol was developed for detecting the presence of schistosoma mansoni sporocysts in intermediate host snails of the genus biomphalaria. to accomplish this, rdna genes encoding the 18s rrna of s. mansoni and biomphalaria alexandrina from egypt were sequenced, as were 18s-encoding genes of the 13-16-r1 and salvador strains of biomphalaria glabrata. based on a comparison of host and parasite sequences, a nested set of pcr primers was designed to allow spe ... | 1997 | 9194817 |
| pcr amplification of the mitochondrial dna minisatellite region to detect schistosoma mansoni infection in biomphalaria glabrata snails. | schistosoma infection in biomphalaria glabrata can be detected by either exposing snails to light to induce cercarial shedding or by squeezing them between glass slides to detect parasites in the digestive gland and other regions. the methods available are inefficient for identification of prepatent infections and do not allow the diagnosis of infection in snails that die before arriving in the laboratory. furthermore, infection is undetectable after migration of sporocysts from the head-foot re ... | 1997 | 9194818 |
| anthraquinones in rheum palmatum and rumex dentatus (polygonaceae), and phorbol esters in jatropha curcas (euphorbiaceae) with molluscicidal activity against the schistosome vector snails oncomelania, biomphalaria and bulinus. | hot water extracts of rheum plamatum and rheum dentatus (from china) showed molluscicidal activity against the snails oncomelania hupensis, biomphalaria glabrata and bulinus globosus, which are vectors of schistosoma japonicum, s. mansoni and s. haematobium, respectively. activity was correlated with antraquinones which were identified by hplc: rhein and chrysophanol-anthron were most active (> 50% dead snails after 2 days in a 0.03% solution). molluscicidal activity was intermediate with rheum- ... | 1997 | 9472303 |
| observations on the miraxonal attraction exercised by sexually immature or adult biomphalaria glabrata infected or not by schistosoma mansoni. | the influence of age and the presence of secondary sporocysts in the miraxonal attraction exercised by biomphalaria glabrata on miracidia of schistosoma mansoni of the bh strain were studied. | 1997 | 9497557 |
| a laboratory-based approach to biological control of snails. | development of schistosoma mansoni in the intermediate host biomphalaria glabrata is influenced by a number of parasite and snail genes. understanding the genetics involved in this complex host/ parasite relationship may lead to an often discussed approach of introducing resistant b. glabrata into the field as a means of biological control for the parasite. for the snail, juvenile susceptibility to the parasite is controlled by at least four genes, whereas one gene seems to be responsible for ad ... | 1997 | 9566236 |
| schistosoma japonicum: in vitro cultivation of miracidium to daughter sporocyst using a biomphalaria glabrata embryonic cell line. | in vitro cultivation of schistosoma japonicum miracidia to the mother sporocyst (ms) and then to the daughter sporocyst (ds) stage was achieved using the biomphalaria glabrata embryonic (bge) cell line as a coculture system. when comparing the effect of bge cell and ms density on ms development, it was apparent that bge cell density had a highly significant effect on both ms viability and growth. viability and growth rate of ms cultured under high cell density conditions (350 cells/mm2) were alm ... | 1997 | 9326883 |
| a comparative study of the organic acid content of the hemolymph of schistosoma mansoni-resistant and susceptible strains of biomphalaria glabrata. | the freshwater snail biomphalaria glabrata is an intermediate host of the trematode schistosoma mansoni. however, some strains of b. glabrata are resistant to successful infection by s. mansoni larvae. the present work examines the profile of organic acids present in s. mansoni-resistant and -susceptible strains of b. glabrata, in order to determine whether the type of organic acid present is related to susceptibility. the organic acids were extracted from the hemolymph of two susceptible b. gla ... | 1997 | 9332612 |
| comparative histopathology of biomphalaria glabrata, b. tenagophila and b. straminea with variable degrees of resistance to schistosoma mansoni miracidia. | a comparative histopathological study of three snails species--biomphalaria glabrata, b. tenagophila and b. straminea--which had been infected with schistosoma mansoni miracidia revealed similar qualitative features; consisting of areas of sporocyst proliferation and differentiation associated with reactive host reaction, at the time they were actively eliminating great number of cercariae. however, in specimens that were exposed to miracidia but failed to eliminate cercariae later on, different ... | 1997 | 9361747 |
| heat-shock response in a molluscan cell line: characterization of the response and cloning of an inducible hsp70 cdna. | sublethal heat-shock of cells of the bge (biomphalaria glabrata embryonic) snail cell line resulted in increased or new expression of metabolically labeled polypeptides of approximately 21.5, 41, 70, and 74 kda molecular mass. regulation of this response appeared to be at the transcriptional level since a similar protein banding pattern was seen upon sds-page/fluorographic analysis of polypeptides produced by in vitro translation of total rna from cells subjected to heat shock. using a yeast (sa ... | 1997 | 9367731 |
| phenoloxidase activity in the reproductive system of biomphalaria glabrata: role in egg production and effect of schistosome infection. | infection by larval trematodes often causes a cessation of egg production in its molluscan intermediate host and is referred to as parasitic castration. because phenoloxidase (po) has been shown to be involved in egg formation in other invertebrate species, we investigated the role of po in normal egg production in the snail, biomphalaria glabrata, and the effects of schistosoma mansoni infection on the po pathway in this snail. our data showed that po activity in the albumen gland (ag) is initi ... | 1997 | 9379290 |
| human schistosomiasis in puerto rico: reduced prevalence rate and absence of biomphalaria glabrata. | a combined epidemiologic and malacologic survey of schistosomiasis in puerto rico was carried out in areas where previous surveys had reported the prevalence of the disease. this limited survey, with 495 persons examined, found a low prevalence (0.6%) of schistosoma mansoni infections. the infections were restricted to three people more than 36 years of age. no infections were detected in children 16 years of age or less, and this cohort comprised 57.8% of the study group. malacologic surveys of ... | 1997 | 9392596 |
| 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 ... | 1997 | 9238039 |
| [the resistance of biomphalaria glabrata to schistosoma mansoni infection: variations in the prepatent period and in compatibility]. | biomphalaria glabrata from belo horizonte, minas gerais, brazil, reared in laboratory, has a level of infection of 90% when exposed to 20 miracidia of the autochibonous le strain. the prepatent period was of 5 to 7 weeks whereas 5 to 10% of exposed snails do not shed cercariae. the eggs of negative snails were collected and the progeny was again submitted to individual infection with 20 miracidia. the mean of infection from f14 to f20 was of 43.6%. histological sections from f12, f14 and f15 sna ... | 1997 | 9265222 |
| partially degraded dna of parasitological interest serves as an adequate template for the production of random amplified polymorphic dnas (rapds). | genomic dna was extracted from schistosoma mansoni adult worms and deliberately degraded by sonication. samples with varying average molecular weight were subjected to rapd (randomly amplified polymorphic dna) analysis using the primer 3307 (5'-agtgctacgt-3') and other primers. reproducible and complex dna banding patterns were obtained, irrespective of the extent of dna degradation. the same amplification protocol was employed with naturally degraded biomphalaria glabrata genomic dna and the pr ... | 1997 | 9267422 |
| schistosoma mansoni: cercarial shedding patterns from a mixed infection of biomphalaria glabrata with two (early and late) chronobiological variants. | the cercarial emergence rhythms of schistosoma mansoni were analyzed for mixed infection of the snail biomphalaria glabrata with two chronobiological strains, one with an early shedding pattern and the other with a late shedding pattern. under these conditions, each parasite strain kept its own circadian cercarial emergence pattern. when the chronobiological variants were of the same species, no interference between the trematode larvae occurred during the cercarial emergence process. these resu ... | 1997 | 9134557 |
| [relationship between pathogenicity of schistosoma mansoni in mice and the susceptibility of the vector mollusk. iv--infectiousness of miracidia]. | the infection ability of miracidia of bh and sj strains of s. mansoni, obtained from mice infected with cercariae taken from biomphalaria glabrata and biomphalaria tenagophila, genetically selected for susceptibility is compared with the infection ability of miracidia obtained from mice infected with larvae from non-selected mollusks. | 1997 | 9629726 |
| quantification of the population and phagocytary activity of hemocytes of resistant and susceptible strains of biomphalaria glabrata and biomphalaria tenagophila infected with schistosoma mansoni. | among the determinant factors in the resistance and susceptibility of biomphalaria to schistosoma mansoni, hemocytes play an important role. aiming at studying s. mansoni/biomphalaria interactions related to hemocytes, the first step is certainly connected with the standardization of this cell population in uninfected biomphalaria. in this way, quantification of this cell population in hemolymph, as well as its phagocitary capacity, have been determined for the first time. furthermore, using sus ... | 1997 | 9640781 |
| [control of intestinal schistosomiasis in martinique island]. | the presence of schistosomiasis mansoni is known in martinique since the beginning of the xxth century. a general survey of the distribution of the disease was carried out in 1977 and showed a mean prevalence of 12% (coprology and serology taken together) in the whole of the island. following this survey, an integrated control programme associating sanitary education, detection and treatment of patients and improved sanitation, was developed. in addition, a biological control programme against t ... | 1997 | 9587606 |
| [a malacological survey in city parks in belo horizonte, minas gerais, brasil] | the greater metropolitan area of belo horizonte currently contains 18 city parks (also known as "ecological parks") with various bodies of water (lakes, springs, streams, etc). initial research in 17 of these parks showed the occurrence of intermediate mollusk hosts for schistosoma mansoni in at least 4. monthly captures done from august 1994 to february 1996 showed the following results for these planorbids: julien rien park: 1,145 specimens of biomphalaria glabrata (2 to 13 mm); betânia park: ... | 1997 | 10886861 |
| change in schistosome sex ratio under the influence of a biotic environmental-related factor. | schistosoma mansoni is a dioecious trematode responsible for intestinal schistosomiasis in man. the sex ratio was determined for s. mansoni adults derived from cercariae obtained from infected biomphalaria glabrata maintained in the presence of the nonvector molluse. marisa cornuarietis. the presence of m. cornuarietis is responsible for enhanced growth of b. glabrata and for a change in the sex ratio of the schistosome, which becomes more male-biased as compared to control snails maintained in ... | 1997 | 9105300 |
| in vivo and ectopic encystment of echinostoma revolutum and chemical excystation of the metacercariae. | in vivo and ectopic encystment of the cercariae of echinostoma revolutum from lymnaea elodes snails in indiana and chemical excystation of the metacercariae were studied. in vivo encystment occurred in adults of biomphalaria glabrata and helisoma trivolvis (colorado strain) snails and in neonatal and juvenile l. elodes snails. these results were expected because 37-collar-spined echinostoma species show broad specificity in their second intermediate gastropod hosts. encysted metacercariae of e. ... | 1997 | 9105306 |