Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| schistosoma mansoni: use of a cloned ribosomal rna gene probe to detect restriction fragment length polymorphisms in the intermediate host biomphalaria glabrata. | adult susceptibility of biomphalaria glabrata to schistosoma mansoni infection is controlled by simple mendelian genetics. in this study a molecular approach was used to determine the degree of genetic variation between well-defined lines of b. glabrata which are either resistant (10-r2) or susceptible (m-line) to s. mansoni infection. a cloned probe psm389, which contains part of the s. mansoni small ribosomal rna gene and a portion of the nontranscribed spacer was found to cross-hybridize with ... | 1991 | 1680745 |
| schistosoma mansoni and biomphalaria glabrata have some common epitopes. i. common epitopes are present on the surface of early stages of s. mansoni. | 1. the presence of snail and glycocalyx antigens in the schistosoma mansoni cercarial surface and their permanence throughout development in vitro and in vivo was investigated. 2. rabbit antisera raised against two fractions of glycocalyx released from cercariae and biomphalaria glabrata soft tissues or haemolymph were obtained. 3. all four antisera bound to cercariae and schistosomula kept in vitro or in vivo for up to 24 hr. 4. no binding to schistosomula kept in vivo for 5 days or longer was ... | 1991 | 1726079 |
| 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 ... | 1992 | 1738052 |
| isolation and functional characterization of snail hemocyte-modulating polypeptide from primary sporocysts of schistosoma mansoni. | infection with larval trematodes has been shown to inhibit several snail-host defences, including hemocyte phagocytosis, cytotoxicity, motility, and adherence. certain plasma factors which mediate snail defence responses, and which may be produced by host hemocytes, also appear to be altered by these parasites. in this study we present protocols for the isolation of 2 proteins from larval schistosoma mansoni excretory-secretory (es) products and detail the effects of these components on biomphal ... | 1991 | 1775150 |
| thermal preferences of resistant and susceptible strains of biomphalaria glabrata (gastropoda) exposed to schistosoma mansoni (trematoda). | the thermal preferences of two strains of the snail biomphalaria glabrata, one resistant to, and one susceptible to, the parasite schistosoma mansoni were determined in an aquatic thermal gradient. snails were tested without exposure to the parasite, and 2 h and 5 weeks after exposure to trematode miracidia. the mean temperature selected by susceptible strain snails 2 h post-exposure tended to be lower than that of unexposed controls, although this was not statistically significant. in this stra ... | 1991 | 1780172 |
| the occurrence of schistosomin, an antagonist of female gonadotropic hormones, is a general phenomenon in haemolymph of schistosome-infected freshwater snails. | in haemolymph of lymnaea stagnalis, parasitized with the digenetic trematode parasite trichobilharzia ocellata, a neuropeptide (schistosomin) occurs which antagonizes female gonadotropic hormones, e.g. calfluxin (cafl). by means of an ultracytochemical hormone-assay, the cafl assay, it was demonstrated that the occurrence of schistosomin is a general phenomenon in schistosome-infected freshwater snails. haemolymph of the schistosomiasis-transmitting snail species biomphalaria glabrata and b. pfe ... | 1991 | 1780174 |
| [relationship between the pathogenicity of schistosoma mansoni in mice and the susceptibility of the vector mollusc. i. cercariae infectivity and worm burden]. | the possible influence of the immune mechanisms of the molluscs on the development of the sporocysts and the resultant behavior of the adult worm in the vertebrate host were studied. two strains of schistosoma mansoni (bh and sj) were used. these were genetically selected for their susceptibility and maintained, respectively, in biomphalaria glabrata and biomphalaria tenagophila, the natural invertebrate hosts. experimental groups of mice infected with cercariae proceeding from the two species o ... | 1991 | 1820625 |
| [identification of a new focus of schistosoma mansoni. (municipality of nova lima, mg, brazil]. | the detection of a new transmission focus of schistosomiasis in nova lima town, minas gerais state, brazil, is reported. the search of snail intermediate hosts in banqueta do bananal a small locality of boa vista neighbourhood detected 356 specimens of biomphalaria glabrata, with a infection rate of 8.4%. in hundred-sixty-two patients stool examinations (kato-katz method) were done, showing ninety-one patients with eggs of schistosoma mansoni in their feces. the integrated action of local reside ... | 1991 | 1842844 |
| [effects of eugenol and derivatives on biomphalaria glabrata]. | biomphalaria glabrata snails and egg-masses were exposed, for six to twenty-four hours to concentrations of 1, 10, 100 and 1000 ppm of eugenol, o-methyleugenol, o-benzyleugenol and dehydrodieugenol. only at 10 ppm o-benzyleugenol enhanced mortality of snails and egg-masses. the other substances showed ovicidal and molluscicidal activity only at 100 and 1000 ppm concentrations, causing a significant cardiac frequency reduction in snails after 6 to 24 hours of exposure as well as perduring low car ... | 1991 | 1844101 |
| [repopulation of breeding habitats of biomphalaria glabrata after treatment with niclosamide]. | experiments were undertaken both in the laboratory and in the field between 1980-1984 to evaluate the causes of repopulation of breeding places of biomphalaria glabrata following treatment with niclosamide. laboratory bioassays showed that the susceptibility to emulsifiable niclosamide of b. glabrata collected monthly from an irrigation ditch system varied during the year. lethal concentrations (lc90) ranged between 0.15 mg/l-1 and 0.60 mg/l-1. statistically significant differences (alpha = 0.01 ... | 1991 | 1844951 |
| physiologic studies of snail-schistosome interactions and potential for improvement of in vitro culture of schistosomes. | despite extensive efforts to develop suitable media for rearing the intramolluscan stages of schistosomes, successful in vitro culture of these parasites remains elusive. recent 31p nmr studies demonstrated that the levels of free phospholipids, particularly phosphatidylcholine, in the digestive gland of the snail, biomphalaria glabrata, were dramatically reduced when the host was infected with schistosoma mansoni. it was speculated that absorption of host phosphatides may be an important source ... | 1991 | 1869492 |
| 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 ... | 1991 | 1919922 |
| influence of the nontarget mollusc marisa cornuarietis on the hourly cercarial production of schistosoma mansoni from biomphalaria glabrata. | a comparative study of hourly cercarial productivities of schistosoma mansoni from infected biomphalaria glabrata was carried out in the presence of either healthy b. glabrata (control) or healthy marisa cornuarietis (experimental). the results showed that, with m. cornuarietis, almost all the hourly cercarial productivities increased by a factor varying from 1.3 to 2.5 without modification of the shedding period. | 1991 | 1919935 |
| schistosoma mansoni: influence of infection on levels of translatable mrna and on polypeptide synthesis in the ovotestis and albumen gland of biomphalaria glabrata. | larval trematode infection causes a disruption of normal reproductive activity in the molluscan intermediate host. because relatively little is known about the dynamics of this host-parasite interaction, the effect of schistosoma mansoni infection on translatable mrna pools and on polypeptide synthesis was examined in the ovotestis (ot) and albumen gland (ag) of biomphalaria glabrata. total rna was isolated from ots and ags from uninfected control snails and snails at 14, 21, and 28 days postinf ... | 1991 | 2026214 |
| tegumental surface modulation in schistosoma mansoni primary sporocysts in response to ligand binding. | the clearance of host molecules from the surface of a parasite constitutes a potential immune evasive strategy. the possibility that certain ligands, when bound to the tegument of schistosoma mansoni primary sporocysts, could induce such a modulating effect was investigated. live, in vitro cultured primary sporocysts were first treated with either snail host biomphalaria glabrata plasma, an anti-sporocyst monoclonal antibody (moab iii-1), or concanavalin a (con a). the capacity of these primary ... | 1991 | 2052402 |
| ecdysteroids as regulators of host and parasite interactions: a study of interrelationships between schistosoma mansoni and the host snail, biomphalaria glabrata. | ecdysteroids have been detected in trematode parasites and in several species of gastropod snails. the potential role of these and other hormones as regulators of host/parasite interactions is discussed. this study considers the role of ecdysteroids in the host parasite interactions between schistosoma mansoni and biomphalaria glabrata interactions. beta-ecdysterone was found to be effective in stimulating host location activities in s. mansoni miracidia and in enhancing growth and egg productio ... | 1991 | 2052849 |
| a comparison of the glycolipid compositions of cercarial and adult schistosoma mansoni and their associated hosts. | glycolipid patterns of cercarial and adult schistosoma mansoni were determined and compared with those of biomphalaria glabrata snails and mouse (balb/c strain) red blood cells by high-performance thin-layer chromatography. differences in glycolipid content were found between cercariae and adult worms and between these stages and their respective host tissues. | 1990 | 2074137 |
| structural homology of tropomyosins from the human trematode schistosoma mansoni and its intermediate host biomphalaria glabrata. | molecular mimicry has been considered as a possible way for parasites to escape host immune responses. this work concerns the characterization of protein determinants shared by schistosoma mansoni and its intermediate host biomphalaria glabrata. parasite (sm39) and mollusc (bg 39) cross-reactive proteins were identified and shown to induce in rabbit and mouse, antibodies specific for invertebrate determinants. ultrastructural studies demonstrated that antibodies to sm39 specifically bound to mus ... | 1990 | 2090946 |
| influence of larval schistosomes on polysaccharide synthesis in albumin glands of biomphalaria glabrata. | an in vitro bioassay was used to examine [14c]glucose incorporation into polysaccharides in albumen glands (ags) of susceptible m-line biomphalaria glabrata infected with the nmri strain of schistosoma mansoni. polysaccharide and galactogen synthesis were unaffected by larval trematode infection in ags of snails at days 14, 21, and 28 post-infection (p.i.) when compared to uninfected controls. further experiments were conducted to determine if daughter sporocysts, hypothesized to be primary medi ... | 1990 | 2092292 |
| effect of temperature on the reproduction of the snail biomphalaria glabrata. | 1. the reproduction of the snail biomphalaria glabrata, one of the intermediate hosts of schistosoma mansoni, was evaluated under laboratory conditions by measuring egg production, number of ovipositions, number of eggs per oviposition, and hatching rate using a latin square design with five different temperature treatments. this permitted the elimination of occasional variation in oviposition due to manipulation or a priori group. 2. egg production and spawning rates were higher at temperatures ... | 1990 | 2095294 |
| lectin binding to cells of schistosoma mansoni sporocysts and surrounding biomphalaria glabrata tissue. | the binding of different lectins to the surface of mother and daughter sporocysts of schistosoma mansoni (trematoda) and to cells of its intermediate host biomphalaria glabrata (gastropoda) was investigated. the test system consisted of several biotin-labeled lectins, an avidin-biotin-peroxidase complex and 3,3'-diaminobenzidine. the fixatives used were formalin, bouin's and zenker's solutions; unfixed material was also studied. most lectins reacted equally with host tissue and parasite tissue. ... | 1990 | 2105357 |
| influence of intramolluscan larval stages of echinostoma liei on the infectivity of schistosoma mansoni cercariae. | during co-infection of biomphalaria glabrata with schistosoma mansoni and echinostoma liei, s. mansoni cercariae released before the complete resorption of s. mansoni sporocysts show a very strong decrease of their infectivity in mice. under conditions of high interspecific competition (i.e. when the snails are infected by e. liei 8 days after infection by s. mansoni), the mean overall worm return is five times lower than that of the control experiment. a marked decrease of the infectivity of ce ... | 1990 | 2110945 |
| dynamics of the leukocytic response of biomphalaria glabrata during the larval development of schistosoma mansoni and echinostoma liei. | the daily evolution of the number of hemocytes in biomphalaria glabrata was ascertained under three conditions: uninfected snails, snails infected with schistosoma mansoni, and snails infected with echinostoma liei. the results show differences between the three experiments as well as in the average hemocyte density over the whole experimental period, as in the temporal dynamics of circulating hemocyte number. specifically, it appears that the development of e. liei in b. glabrata induces a dens ... | 1990 | 2112576 |
| [molluscacide and cercariacide activity of different species of eucalyptus]. | hydrolates and essential oils of several eucalyptus species were tested on adult snails and egg masses of biomphalaria glabrata, and cercaria of schistosoma mansoni. these products were obtained by vapor dragging. eight out of 21 hydrolates presented activity on snails, nine on egg masses and three on cercaria at 1:4 dilutions. eleven oils were active on both snails and egg masses at 20 ppm concentrations. the hydrolate of e. deanei was active both on snails, egg masses and cercaria at 1:4 dilut ... | 1990 | 2133583 |
| in vitro effect of larval schistosoma mansoni excretory-secretory products on phagocytosis-stimulated superoxide production in hemocytes from biomphalaria glabrata. | the in vitro production of the reactive oxygen metabolite superoxide (o2-) was confirmed in hemocytes from the schistosome intermediate host biomphalaria glabrata. active forms of the enzyme superoxide dismutase (sod) inhibited reduction of nitroblue tetrazolium (nbt) to formazan in cells that had phagocytozed zymosan particles, whereas an inactivated form of sod did not. moreover, based on the prevalence of o2(-)-positive hemocytes and the relative intensity of nbt staining reactions, hemocytes ... | 1990 | 2174969 |
| molluscicidal and antischistosomal activities of zingiber officinale. | experiments were conducted to study the major constituents of zingiber officinale responsible for its molluscicidal activity and the effect of the active component on different stages of schistosoma mansoni. gingerol and shogaol exhibited potent molluscicidal activity on biomphalaria glabrata. gingerol (5.0 ppm) completely abolished the infectivity of schistosoma mansoni miracidia and cercariae in b. glabrata and mice, respectively, indicating that the molluscicide is capable of interrupting sch ... | 1990 | 2236291 |
| praziquantel treatment of biomphalaria glabrata infected with schistosoma mansoni--influence on snail fecundity. | praziquantel, administered over a 72 h period in the food of mature biomphalaria glabrata harbouring 7-week-old schistosoma mansoni infections, dramatically reduced the numbers of cercariae shed. doses of 20-30 micrograms/g body weight (including shell weight) reduced shedding by 85-95% over 5 weeks before recovery was evident. suppression of cercarial shedding in these infections was accompanied by the temporary recovery of the snail reproductive regression due to s. mansoni infection. snail fe ... | 1990 | 2263415 |
| schistosoma mansoni modulation of phagocytosis in biomphalaria glabrata. | both short-term (3 hr) exposure of biomphalaria glabrata snails (m-line and 13-16-r1) to schistosoma mansoni (pr1) miracidia and in vitro incubation of parasite sporocysts with host hemolymph components altered host phagocytic ability. hemocytes obtained from susceptible (m-line) snails that had been exposed to parasite miracidia for 3 hr showed reduced levels of phagocytosis of yeast cells in vitro compared to hemocytes from unexposed individuals. incubation of whole hemolymph with sporocysts i ... | 1990 | 2299527 |
| schistosoma mansoni: influence of biomphalaria glabrata size on susceptibility to infection and resultant cercarial production. | biomphalaria glabrata snails of the same age, but different sizes, were used to determine size-related susceptibility to schistosoma mansoni miracidial infection and the influence of snail size on total cercarial production. snails with shell diameters from less than 5 to greater than 17 mm were individually exposed to one or several miracidia, depending on the experiment. in snails exposed to multiple numbers of miracidia, the percentage of snails which developed patent infections was lower in ... | 1990 | 2311711 |
| differential binding of hemolymph proteins from schistosome-resistant and -susceptible biomphalaria glabrata to schistosoma mansoni sporocysts. | humoral factors have been associated with resistance of biomphalaria glabrata to infection by schistosoma mansoni. the goal of this study was to determine which serum (cell-free hemolymph) proteins bind to the surface of s. mansoni sporocysts. for this, 125i-labeled serum from schistosome-resistant (10-r2) and -susceptible (m-line) b. glabrata was incubated with sporocysts, washed, and then subjected to sds-page and autoradiography. other samples examined included radiolabeled 10-r2 and m-line s ... | 1990 | 2319423 |
| biological control of biomphalaria glabrata by thiara granifera under laboratory conditions. | the effect of the snail thiara granifera on the snail biomphalaria glabrata, intermediate host of schistosoma mansoni in the dominican republic, was evaluated. plastic aquaria, 3 and 1.5 gallons in capacity, were used. the aquaria were either unpartitioned or partitioned by a fine screen into two equal compartments, and the two snail species were introduced in different proportions. the results over a 1-year period showed that t. granifera effectively reduced the fecundity of b. glabrata, especi ... | 1990 | 2339245 |
| comparative glucose tolerance studies in the freshwater snail biomphalaria glabrata: influence of starvation and infection with the trematode schistosoma mansoni. | the dynamic reactions of b. glabrata on intravasal loads of 20-1000 micrograms glucose.g live fresh wt-1 were studied in standard fed snails (sfs). starved snails (ss) and snails infected with s. mansoni (is) were given 100-500 micrograms glucose.g fresh live wt-1. mean hemolymph glucose level was 12.1 mg.100 ml-1 in sfs. it was not significantly lower in ss (10.7 mg.100 ml-1), but significantly reduced in is (8.5 mg.100 ml-1). since hemolymph volumes were significantly increased in ss, the amou ... | 1990 | 2355116 |
| the effect of schistosome excretory-secretory products on biomphalaria glabrata hemocyte motility. | excretory-secretory (e-s) products contained in supernatants from in vitro cultured schistosoma mansoni primary sporocysts were assayed for their effects on the in vitro motility of biomphalaria glabrata hemocytes. both whole (unfractionated) and fractionated e-s products were tested in modified boyden chemotaxis chambers. e-s product fractionation was accomplished using both membrane ultrafiltration (mf) and high-pressure liquid chromatography (hplc). transformation (tr) products, but not those ... | 1990 | 2376664 |
| 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 ... | 1990 | 2394975 |
| isolation and partial characterization of an antigen shared between schistosoma mansoni, fasciola hepatica, and biomphalaria glabrata. | an antigen was isolated and partially characterized from adult schistosoma mansoni which immunologically cross-reacted with fasciola hepatica and biomphalaria glabrata, a schistosome intermediate snail host. the antigen was isolated from a solubilized freeze-thaw preparation containing 0.5% triton x-100 by passage through a cnbr-activated sepharose 4b column coupled with rabbit igg prepared against a homogenate of b. glabrata hepatopancreas. the eluted antigen (designated as smw-53p) stained wit ... | 1985 | 2419536 |
| interactions between the plasma proteins of biomphalaria glabrata (gastropoda) and the sporocyst tegument of schistosoma mansoni (trematoda). | the tegumental surface of schistosoma mansoni sporocysts is the site of both nutritive and immunological interactions with haemolymph cells and plasma of biomphalaria glabrata, the schistosome intermediate host. within minutes of being placed in host plasma, sporocysts acquire plasma antigens, and within 3 h host plasma antigens are present on the surface at near steady state. though a wide variety of peptides is acquired, there is selection. furthermore, some differences occur in the peptides a ... | 1986 | 2426650 |
| schistosoma mansoni shares a protective oligosaccharide epitope with freshwater and marine snails. | the expression of similar antigenic determinants by trematode parasites and their intermediate (invertebrate) or definitive (vertebrate) hosts has been previously reported. studies of experimental and human infection by the parasite schistosoma mansoni have revealed the strong immunogenicity of a surface antigen with a relative molecular mass (mr) 38,000 (38k). here we provide evidence that the important protective epitope of the 38k molecule is expressed by the uninfected intermediate host of s ... | 1986 | 2429191 |
| widespread antigenic cross-reactivity between plasma proteins of a gastropod, and its trematode parasite. | evidence obtained earlier with immunofluorescence and immunoelectron microscopy was interpreted to imply molecular mimicry of the host biomphalaria glabrata by the parasite schistosoma mansoni. using western blotting, we find that "mimicry" is due to widespread shared epitopes. furthermore, at least one individual plasma protein of b. glabrata shares epitopes with the majority of plasma proteins in the mollusc. the widespread antigenic determinants may be carbohydrates. caution is warranted when ... | 1987 | 2442042 |
| schistosoma mansoni antigens recognized in biomphalaria glabrata hemolymph by monoclonal antibodies. | in order to identify and characterize schistosoma mansoni antigens in biomphalaria glabrata, we examined 19 murine monoclonal antibodies (mabs) for specific binding to schistosome larvae. none of the murine mabs induced by infection or by immunization with a crude cercarial antigen (cca) served this purpose. two mabs out of 9 (kcsme22-3 and kcsme22-4) induced by soluble egg antigens reacted with cca but not with normal snail (nsn) extract. we selected these 2 for studies on detection and charact ... | 1989 | 2472748 |
| gp38, p28-i and p28-ii: candidates for a vaccine against schistosomiasis. | three antigens protective against schistosoma mansoni have been extensively characterized. the schistosomulum surface antigen gp38 possesses an immunodominant carbohydrate epitope of which the structure has been defined. protection can be achieved via the transfer of monoclonal antibodies recognizing the epitope or by immunization with anti-idiotype monoclonal antibodies. the glycan epitope is shared with the intermediate host, biomphalaria glabrata as well as being present on other molluscs, in ... | 1987 | 2474122 |
| biological control of biomphalaria glabrata and b. straminea by the competitor snail thiara tuberculata in a transmission site of schistosomiasis in martinique, french west indies. | in martinique, intestinal schistosomiasis was discovered at the beginning of this century. the intermediate host snail, biomphalaria glabrata, was considered in the past as a common species in the different habitats of the island, but during the last decade it has been found only in water-cress beds. several of these water-cress cultures contained mixed populations of b. glabrata and b. straminea. moreover, these habitats also constituted transmission sites for schistosoma mansoni infection. in ... | 1989 | 2513787 |
| [resistance to desiccation of biomphalaria glabrata adults infested by various miracidia of schistosoma mansoni]. | 1200 adult biomphalaria glabrata were submitted during 6 weeks to anhydrobiosis condition. some snails were healthy, some were previously infected 3 days or 12 days ago with 8 +/- 2 miracidia of schistosoma mansoni, others were shedding cercariae. the snails were put on soil or buried into hermetically closed, or ventilated, plastic boxes. there was no survival of snails kept in sealed boxes, or among positive snails, but 44% of control healthy snails and 40.6% of infected (for 3 or 12 days) sna ... | 1989 | 2517564 |
| [natural infection of wild rodents by schistosoma mansoni]. | in planalto, a small locality in the interior of the bahia state, brazil, 47% of sylvatic rodents were found to be naturally infected with schistosoma mansoni, whereas the prevalence of the infection in the inhabitants of the area was 3.26%. the rodents (nectomys) live near the houses, in contact with water, passing viable schistosome eggs in the stools. worm burden is variable amongst such rodents. periovular granulomas are small, especially in liver and intestines, and hepatic fibrosis is mild ... | 1989 | 2517565 |
| a potential vector of schistosoma mansoni in uruguay. | susceptibility experiments were carried out with a biomphalaria straminea-like planorbid snail (biomphalaria aff. straminea, species inquirenda) from espinillar, near salto (uruguay), in the area of the salto grande reservoir, exposed individually to 5 miracidia of schistosoma mansoni (sj2 and bh2 strains). of 130 snails exposed to the sj2 strain, originally infective to biomphalaria tenagophila, 30 became infected (23%). the prepatent (precercarial) period ranged from 35 to 65 days. the cercari ... | 1989 | 2520826 |
| the biochemical ecology of biomphalaria glabrata, a snail host of schistosoma mansoni: short chain carboxylic and amino acids as phagostimulants. | 1. a buccal mass olfactometer was used to investigate the responses of the fresh-water pulmonate snail biomphalaria glabrata to carboxylic and amino acids. 2. the snails proved very discriminating as only 6 (14.6%) of the 41 chemical species tested were effective as phagostimulants. these are ranked as follows in order of potency:- butanoate greater than propanoate greater than d-malate greater than 2-hydroxybutanoate = l-tartrate = l-aspartate. 3. the structure-activity relationships of the act ... | 1989 | 2570673 |
| effect of infection with trichobilharzia ocellata and schistosoma mansoni on the ultrastructure of the albumen gland of their respective hosts, lymnaea stagnalis and biomphalaria glabrata. | the albumen gland, a female accessory sex gland of pulmonate snails, produces the perivitelline fluid. the ultrastructure of the albumen glands of control and infected specimens of lymnaea stagnalis and biomphalaria glabrata was studied. the albumen gland of l. stagnalis contains two types of secretory cells--light (active) and dark (inactive)--and two types of supporting cells--centroacinar and myoepithelial. the secretory cells apparently represent two activity stages of one type of cell. the ... | 1989 | 2606384 |
| ultrastructural evidence for the destruction of schistosoma mansoni sporocysts associated with elevated lysosomal enzyme levels in biomphalaria glabrata. | the activity levels of serum acid phosphtase, aminopeptidase, and lysozyme in a brazilian strain of biomphalaria glabrata were ascertained at 1, 2, and 3 hr after mechanical wounding or injection with albumin on the 30th day postexposure to a compatible strain of schistosoma mansoni miracidia and found to be elevated. parallel transmission electron microscope studies on daughter sporocysts and developing cercariae at these time intervals revealed progressive disintegration of the parasites that ... | 1989 | 2614603 |
| structural analysis of hemolymph proteins from schistosoma mansoni (trematoda)-susceptible and resistant biomphalaria glabrata (gastropoda). | 1. five different molecular weight polypeptides from serum (cell-free hemolymph) of schistosoma mansoni-resistant and susceptible strains of biomphalaria glabrata, were examined by two-dimensional 125i-peptide mapping and high performance liquid chromatography (hplc). 2. peptide mapping indicated that all five radiolabeled polypeptides within and between the two snail strains had similar migration patterns when cleaved with pepsin or alpha-chymotrypsin, thus revealing a shared structural homolog ... | 1989 | 2620499 |
| phagocytosis of yeast by biomphalaria glabrata: carbohydrate specificity of hemocyte receptors and a plasma opsonin. | in vitro phagocytosis of yeast cells by hemocytes of the mollusc biomphalaria glabrata can occur in the absence of plasma, but is enhanced by opsonization in plasma from certain snail strains. we have investigated the carbohydrate specificity of the hemocyte-bound receptor for phagocytosis and the free plasma opsonin using two dominant carbohydrate components of the yeast cell wall (laminarin and mannan). phagocytic uptake in the absence of plasma of both untreated and opsonized yeast is strongl ... | 1989 | 2670623 |
| opsonization of yeast by the plasma of biomphalaria glabrata (gastropoda): a strain-specific, time-dependent process. | phagocytosis of yeast by haemocytes of biomphalaria glabrata, intermediate host of schistosoma mansoni, is influenced strongly by host plasma components, although it can occur without involvement of such factors. plasma from two strains of b. glabrata which are resistant to s. mansoni differs in its opsonic properties from the plasma of a susceptible strain. this may reflect the principles which determine compatibility or incompatibility in this host-parasite system. opsonization is a time-depen ... | 1989 | 2671868 |
| schistosoma mansoni: effect of infection on reproduction and gonadal growth in biomphalaria glabrata. | sexually mature biomphalaria glabrata were exposed to 12 miracidia of schistosoma mansoni, and egg production of snails was monitored over a period of 5 weeks. during the study period, exposed snails grew at approximately the same rate as unexposed controls. castration, as measured by a reduction in the mean number of eggs laid per snail occurred between 14 and 21 days postexposure (pe). the reduction in fecundity in infected snails coincided with the migration and establishment of daughter spor ... | 1989 | 2703029 |
| alterations in hemolymph components in biomphalaria glabrata during long-term infection with schistosoma mansoni. | total protein, hemoglobin, glucose, and urea concentrations in hemolymph of biomphalaria glabrata were studied during a 12-week infection of the snails with schistosoma mansoni. the results suggest an equilibrium between host and parasite metabolism, which is reached after about 6 weeks of infection. during the period studied, the protein spectrum of infected snails showed no difference in quality compared with that of noninfected snails; all fractions were present, and no additional fractions a ... | 1989 | 2710775 |
| re-establishing a life cycle of schistosoma mansoni from cryopreserved larvae. | to study the feasibility of re-establishing a life cycle of schistosoma mansoni (nmri strain) from cryopreserved larvae, schistosomules were suspended in the cryoprotectant 1,2-ethanediol and cryopreserved in liquid nitrogen. mice were injected intramuscularly with samples thawed after 3 days, 3 wk, or 6 mo in liquid nitrogen storage. two to 5% of the cryopreserved larvae and approximately 18% of corresponding unfrozen control larvae developed into adult worms. infectivity did not decrease as a ... | 1989 | 2723921 |
| identification of snails infected with schistosomes by elisa employing monoclonal antibodies: schistosoma mansoni in laboratory snails (biomphalaria glabrata) and in field snails (biomphalaria pfeifferi) from kenya. | an enzyme-linked immunosorbent assay (elisa) employing monoclonal antibodies was used for detecting schistosoma mansoni antigens in hemolymph of laboratory snails (biomphalaria glabrata) in kenya. infected laboratory snails shedding cercariae were differentially identified by elisa from uninfected snails with 100% sensitivity and specificity. prepatent infections were detected by elisa from 2 weeks after exposure to miracidia. thus, elisa revealed infection 3 weeks before maximal patency was rea ... | 1989 | 2742038 |
| 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 ... | 1989 | 2768830 |
| changes in plasma opsonization of yeast after isolation of biomphalaria glabrata in small volumes of water. | 1989 | 2768831 | |
| preliminary observations on a hemolymph factor influencing the infectivity of schistosoma mansoni miracidia. | it has been demonstrated that the infectivity of schistosoma mansoni miracidia for a highly susceptible strain of biomphalaria glabrata was reduced markedly when the miracidia were pretreated with hemolymph from the snail helisoma caribaeum. although the helisoma hemolymph factor(s) responsible for this phenomenon has not been identified with certainty, it appears to be a snail lectin associated with binding sites for n-acetyl-d-glucosamine on the surface of the miracidium. hemolymph from uninfe ... | 1986 | 2872788 |
| schistosoma mansoni and its intermediate host biomphalaria glabrata express a common 39 kilodalton acidic protein. | two schistosoma mansoni proteins of 43 and 39 kda (sm43 and sm39) were shown to react with rabbit antibodies produced against biomphalaria glabrata proteins. two-dimensional gel electrophoresis of miracidial proteins indicated that sm43 and sm39 were acidic proteins (pi 4.8 and 4.9 respectively) and were in vitro translated from miracidial messenger rna in the same molecular forms. sm43 and sm39 were expressed by all parasite stages of s. mansoni. using anti-sm43 and anti-sm39 mouse sera, we dem ... | 1989 | 2911278 |
| effects of schistosoma mansoni on the nutrition of its intermediate host, biomphalaria glabrata. | biomphalaria glabrata infected with schistosoma mansoni and maintained on an artificial diet of spirulina alga displayed reduced growth during the 5 wk following patency. food consumption per unit snail weight was unaffected. infected snails also failed to lay eggs. no difference in percentage of assimilation was observed between control and infected individuals, but infected snails had significantly decreased gross conversion efficiencies. the effects of infection on nutrition of b. glabrata we ... | 1989 | 2926600 |
| 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 ... | 1985 | 2981947 |
| schistosoma mansoni: comparison of a caribbean and african strain and experimental crossing based on compatibility with intermediate hosts and rattus rattus. | to elucidate changes relative to compatibility with intermediate and definitive hosts affecting schistosoma mansoni since it was introduced to the new world, the compatibility of s. mansoni from africa (the cameroons), from the caribbean (guadeloupe), and those resulting from experimental crosses with the gastropods biomphalaria glabrata and b. pfeifferi has been studied. results show that s. mansoni, regardless of its origin or its usual snail host, always infects b. pfeifferi more successfully ... | 1986 | 3082664 |
| 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 ... | 1986 | 3087765 |
| serological studies of the antigens prepared from biomphalaria glabrata snails infected and uninfected with schistosoma mansoni. i. indirect immunofluorescent antibody test using infected snail and adult worm antigens. | 1987 | 3106521 | |
| [current risks in the introduction of schistosomiasis into french guiana]. | at the moment, it seems unlikely that there is a possibility for schistosomiasis implantation in french guiana. the reasons to this are both the number of the immigrants infested by schistosoma mansoni which is quite low and the disappearance of the intermediate host biomphalaria glabrata. the disappearance of the species may be a temporary one. | 1987 | 3111733 |
| serological studies of the antigens prepared from biomphalaria glabrata snails infected and uninfected with schistosoma mansoni. ii. double diffusion technique using cercarial, adult worm, infected and uninfected snail antigens. | 1987 | 3121764 | |
| schistosomiasis mansoni in the dominican republic; prevalence and intensity in the city of higuey by coprological and serological methods. | the prevalence and intensity of infection with schistosoma mansoni were determined in a sample of the population of the city of higuey, dominican republic. the quantitative formol-ether stool sedimentation technique of ritchie, as modified by knight et al., was performed on stools from 1,025 (65.5%) of 1,563 individuals greater than 1 year old. the highest prevalence rates (21.4%) were observed in women 25-29 years old and in men 15-19 years old (20%). the maximum fecal egg count was in the 15- ... | 1987 | 3124312 |
| [susceptibility of biomphalaria glabrata, b. straminea and b. tenagophila to various strains of schistosoma mansoni]. | 1987 | 3130655 | |
| schistosoma mansoni: characterization of clones maintained by the microsurgical transplantation of sporocysts. | five male and 5 female clones of schistosoma mansoni were established and maintained for 3 yr by the serial microsurgical transplantation of sporocysts from infected to uninfected biomphalaria glabrata snails. the clones were initially derived from 10 randomly selected snails with monomiracidial infections. clones were characterized by several criteria, including their infectivities for mice and snails, their cercarial outputs, and their ability to produce immunity in mice. the mean infectivitie ... | 1988 | 3142991 |
| drug resistance in schistosomiasis: a review. | drug resistance associated with the treatment of human schistosomiasis appears to be an emerging problem requiring more attention from the scientific community than the subject currently receives. drug-resistant strains of schistosoma mansoni have been isolated by various investigators as a result of laboratory experimentation or from a combination of field and laboratory studies. review of this data appears to indicate that the lack of susceptibility observed for some of the isolated strains ca ... | 1987 | 3151088 |
| [isolation of a human strain of schistosoma mansoni, sambon,1907]. | in this paper the authors briefly describe a human schistosoma mansoni strain from pará state, brazil. the cirene's strain was capable of infecting 71.4% of the snail vector biomphalaria glabrata (telegrafo's strain) provided by the "evando chagas" institute, belém. the cycle was completed by the infection of six mice. the thoracic and abdominal organs were examined microscopically which demonstrated the passage of the worm into the liver and lungs. the authors discuss the importance of these re ... | 1987 | 3151112 |
| [resistance of biomphalaria peregrina of santa rita do sapucaí, minas gerais, brazil to infection with 3 strains of schistosoma mansoni]. | the descendants of the planorbid snail biomphalaria peregrina, collected in the region of santa rita do sapucaí, minas gerais, brazil, were exposed to miracidia of three strains of schistosoma mansoni: "le" strain from belo horizonte, state of minas gerais; "sj", strain from são josé dos campos, state of são paulo and "al" strain from state of alagoas. of 300 snails exposed to miracidia of the three strains, none was infected. on the other hand, 300 biomphalaria glabrata of the control groups sh ... | 1988 | 3152277 |
| the production of toxic oxygen metabolites by hemocytes of different snail species. | the phagocytic hemocytes of four snail species were investigated for their ability to generate reactive oxygen metabolites upon stimulation by foreign material. hemocytes of the pond snail lymnaea stagnalis and of the garden snail helix aspersa showed a luminol-dependent chemiluminescence (cl) when they phagocytosed zymosan particles. this cl was inhibited by superoxide dismutase (sod) and sodium azide, indicating the involvement of oxygen intermediates. hemocytes of the planorbid snails planorb ... | 1988 | 3169350 |
| strain variation in the infectivity of schistosoma mansoni for biomphalaria glabrata. | 1988 | 3201064 | |
| the host-parasite interface in molluscan schistosomiasis: biotin as a probe for sporocyst and hemocyte surface peptides. | hemocytes of biomphalaria glabrata mediate the internal defensive response which, in resistant snail strains, kills sporocysts of schistosoma mansoni. lacking a gut, the sporocyst has only its tegument to interact with the host milieu (hemolymph). we have, therefore, focused our study on the surface-exposed proteins of hemocytes and sporocyst tegument. using gentle biotinylation of living systems, labelled proteins were studied after sds-page electrophoresis and transfer to nitrocellulose. resul ... | 1988 | 3201703 |
| comparison of haemolymph proteins from schistosoma mansoni (trematoda)-susceptible and resistant biomphalaria glabrata (gastropoda). | 1. whole and haemoglobin (hb)-depleted serum fractions from schistosoma mansoni-resistant (10-r2) and schistosome-susceptible (pr albino, m-line) strains of biomphalaria glabrata were studied using sodium dodecyl sulphate-polyacrylamide gel electrophoresis, immunoblotting and protein assays. 2. whole serum of the pr albino strain had more total protein (11.4 +/- 1.9 mg protein/ml) than the 10-r2 strain (7.8 +/- 3.0 mg protein/ml). 3. there are specific differences in the polypeptide profiles of ... | 1988 | 3224503 |
| influence of experimental illumination and seasonal variation on crossbreeding mating in the snail biomphalaria glabrata. | the crossbreeding activities of the schistosoma mansoni vector snail biomphalaria glabrata were counted in a laboratory aquarium throughout the year under two regimes of 12h light: 12h dark from 7 a. m. to 10 p. m. mating increased significantly in autumn and winter and just missed a significant inverse correlation with temperature and a direct one with locomotion. other similar experiments were carried out to compare mating under various illumination conditions in complete daily cycle measureme ... | 1988 | 3249562 |
| schistosoma mansoni: relationship between cercarial production levels and snail host susceptibility. | two populations of biomphalaria glabrata snails differing slightly in their susceptibility to schistosoma mansoni infection showed dramatic differences in cercarial output per snail. exposed to five or more miracidia, snails from a group with a 90-100% susceptibility rate (group a) produced nearly twice the number of cercariae as those from a group with a 70-80% susceptibility rate (group b). exposure of individual snails to known numbers of miracidia resulted in higher numbers of primary (mothe ... | 1988 | 3366217 |
| secretory protein biosynthesis in snail hemocytes: in vitro modulation by larval schistosome excretory-secretory products. | circulating hemocytes of the snail, biomphalaria glabrata, synthesize and secrete a variety of polypeptides when maintained in vitro in serum-free medium containing [35s] methionine. sds-page/fluorographic analysis of supernatants from resistant snail (10-r2-ok strain) hemocyte cultures revealed the presence of numerous labeled polypeptides ranging in mr from 220 to 14 kda. most of these same proteins were also produced by hemocytes of a susceptible b. glabrata strain (m-line), but the overall r ... | 1988 | 3397815 |
| the genetic variation of compatibility in biomphalaria glabrata and schistosoma mansoni. | interactions between different biomphalaria glabrata stocks and schistosoma mansoni strains were studied. a series of inbred stocks of b. glabrata were characterized as to genetic variations in susceptibility at different ages to a series of different s. mansoni strains. a series of inbred strains of s. mansoni were characterized as to genetic variations in infectivity for b. glabrata stocks at different ages. also described is a process of selection for substrains from a single s. mansoni isola ... | 1987 | 3437352 |
| the effect of seasonal temperature and experimental illumination on reproductive rate in the snail biomphalaria glabrata. | 1. reproduction in the snail biomphalaria glabrata, a vector of schistosoma mansoni, was measured by egg production and other parameters such as number of clutches, eggs per clutch and egg hatching, under laboratory conditions. 2. reproductive rates were highest in terms of total number of eggs, clutches and hatching under constant illumination, followed by conditions similar to the natural rhythm of illumination. the greatest reduction in reproduction occurred in constant darkness. in summary, ... | 1987 | 3455251 |
| behavior of biomphalaria glabrata, the intermediate host snail of schistosoma mansoni, at different depths in water in laboratory conditions. | using three columns of different depths (1.10m, 8.40m and 10.40m), we investigated the possibility of biomphalaria glabrata moving towards deep regions. in the 1.10m column, we noted that locomotion can occur in two manners: 1) when the foot is in contact with the substrate: a) sliding descent; b) sliding ascent; c) creeping descent; d) creeping ascent, 2) when the foot is not in contact with the substrate: a) sudden descent without emission of air bules; b) sudden descent with emission of air b ... | 1987 | 3506633 |
| [the influence of anhydrobiosis on the infestation of biomphalaria glabrata by schistosoma mansoni miracidium]. | 410 biomphalaria glabrata (caribbean strain of guadeloupe) have been infected with one miracidium of schistosoma mansoni, 110 snails, used as controls have been kept into water; the survival rate was 96.4% after 4 weeks and 25.4% produced cercariae. 300 snails were kept on wet soil, and submitted for 6 weeks to progressive desiccation. the survival rate was 23.4% but only 9 of them produced cercariae. periodic variations of the production of male and female larvae have been shown by the weekly t ... | 1987 | 3507918 |
| analysis of the interacting components between larval schistosoma mansoni and schistosome-susceptible and resistant biomphalaria glabrata. | cell-free hemolymph (serum) and hemocytes from schistosoma mansoni-susceptible (pr albino m-line) and resistant (10-r2) strains of biomphalaria glabrata were compared by sds-page, immunoblotting and radioiodination. whole serum of both snail strains is dominated by hemoglobin (hb) (mw = 160 kd). sds-page. of hb-depleted serum indicated that the 10-r2 strain has dominant polypeptides in the 50 to 30 kd range whereas pr albino snails have few low mw proteins. antibodies raised to whole pr albino a ... | 1987 | 3509183 |
| characterization of the 31p nmr spectrum of the schistosome vector biomphalaria glabrata and of the changes following infection by schistosoma mansoni. | the 31p nuclear magnetic resonance (nmr) spectrum of the digestive gland-gonad complex (dgg) of the schistosome vector biomphalaria glabrata was characterized and the effects of infection by schistosoma mansoni noted. the in vivo spectrum was comprised of 11 peaks, 5 downfield and 6 upfield of an external 85% phosphoric acid standard. based on a variety of analytical procedures, the upfield peaks from the standard were demonstrated to be composed of carbamoyl phosphate + a mixture of 3 phosphati ... | 1987 | 3572667 |
| effect of schistosoma mansoni on the gross lipid composition of its vector biomphalaria glabrata. | 1. the total lipid level of the digestive gland-gonad complex of biomphalaria glabrata was reduced by starvation and elevated following infection with schistosoma mansoni. 2. the lipid classes of b. glabrata were phospholipid, monoglyceride, free fatty acid, triglyceride, sterol ester and wax and a single unidentified lipid. the major lipid present in control, starved and infected tissue was sterol. triglyceride was a minor component of control tissue. 3. starvation reduced the relative level of ... | 1987 | 3621903 |
| biomphalaria glabrata: changes in calcium reserves following parasitism by larval schistosoma mansoni. | larval schistosoma mansoni have been shown to induce morphological changes to the internal calcium reserves (in particular the calcareous inclusions in type a calcium cells and to the inner, nacreous layer of the shell) of biomphalaria glabrata within 48 h of miracidial penetration. control experiments have shown that these changes were not due to either the experimental procedures used, mechanical damage or to starvation effects. the effects were, however, analogous to experimentally induced ac ... | 1987 | 3696764 |
| transient non-susceptibility to schistosoma mansoni associated with atrial amoebocytic accumulations in the snail host biomphalaria glabrata. | in some biomphalaria glabrata-schistosoma mansoni combinations snails are susceptible to infection as juveniles, but have variable susceptibility as adults. these snails become non-susceptible at the onset of egg-laying and typically revert to susceptibility in old age. certain stocks of b. glabrata have the capacity to form amoebocytic accumulations in the atrium, and this ability is under genetic control. the atrial amoebocytic accumulations are transitory, typically appearing at onset of egg- ... | 1987 | 3696776 |
| comparative analysis of the schistosoma mansoni and schistosoma bovis cercarial production under the influence of praziquantel. | snails infected with schistosoma mansoni and s. bovis and fed with a food-praziquantel mixture stop shedding cercariae for several days. the cercarial production restarts at different levels after stopping treatment: for some biomphalaria glabrata, the restarting phase of production reaches a high level whereas for other b. glabrata and all of the p. metidjensis, the level of production remains low. histological studies revealed that at the exact moment of this treatment, there is a total destru ... | 1986 | 3716542 |
| quantification of parasite development in the host-parasite system biomphalaria glabrata and schistosoma mansoni. | the visceral mass of biomphalaria glabrata uninfected or infected with schistosoma mansoni was serially sectioned. the amount of hepatopancreas tissue and of parasite tissue was quantified. in pool-infected snails the volume of the whole visceral mass increased very significantly until week 6 and then decreased. due to the growing parasites the volume of the visceral mass in infected snails was at most times higher when compared with uninfected snails of the same dimensions. two weeks p.i. there ... | 1986 | 3716543 |
| comparison of starvation and infection by schistosoma mansoni on tissue viability and the 31p nmr spectrum of biomphalaria glabrata. | 1986 | 3716546 | |
| interaction between the biomphalaria glabrata-schistosoma mansoni host-parasite system and the non-target molluscs: influence on cercarial production. | the cercarial production of schistosoma mansoni by biomphalaria glabrata (target mollusc: tm) was studied in relation to the presence of non-target molluscs (ntm). nine species of ntm were tested. whatever the type of tm-ntm association (lasting association, during prepatent period and production period, association only during the exposure of the molluscs to the miracidia), the presence of ntm involved a significant increase of s. mansoni cercarial production. this increased cercarial productio ... | 1986 | 3746562 |
| shedding patterns of schistosoma mansoni and ribeiroia marini cercariae from a mixed infection of biomphalaria glabrata. | when the snail biomphalaria glabrata is doubly infected by two species of trematode, schistosoma mansoni and ribeiroia marini, each species keeps its own cercarial shedding pattern. emergence of s. mansoni cercariae occurs during the photophase while the r. marini cercariae are shed during the night. these results demonstrate the absence of interference between the mechanisms responsible for the cercarial shedding of each species. the only difference noted concerns a two-hour shift in the peak e ... | 1986 | 3794287 |
| increased oviposition and growth in immature biomphalaria glabrata after exposure to schistosoma mansoni. | biomphalaria glabrata snails are known to be castrated by infection with the trematode parasite schistosoma mansoni 4-6 weeks post-infection. the pattern of oviposition in the first 35 days post-exposure (p.e.) was investigated, in snails aged 14 weeks and measuring 7-10 mm diameter which had not commenced egg-laying, by counting the numbers of eggs laid in 7-day intervals. a group of exposed snails was compared with a control non-exposed group. the exposed group included both parasitized and no ... | 1986 | 3797059 |
| stimulation of schistosoma mansoni miracidia by a 80 kda glycoprotein from biomphalaria glabrata. | soluble extracts of biomphalaria glabrata stimulate in vitro incorporation of methionine in schistosoma mansoni miracidia. evidence is presented that a unique 80 kda glycoprotein representing less than 0.01% of total snail proteins and uniformly distributed in the snail body, is responsible for the observed stimulation. this protein specifically acts on the miracidia and this observation suggests that this glycoprotein influences snail penetration and development of miracidia. however, the prese ... | 1986 | 3807942 |
| effects of environmental calcium on fecundity and cercarial production of biomphalaria glabrata (say) infected with schistosoma mansoni sambon. | biomphalaria glabrata were reared in stock culture and subjected to either 7-day or 60-day acclimation periods in complex caco3 media with calcium values ranging from 1.5 mg/l to 75 mg/l. following 60-day acclimation, snails from series i were each exposed to 8 miracidia of schistosoma mansoni. snails of series ii were each exposed to a single miracidium. snails of both experimental regimens were observed for mortality, growth, rate of infection, and number of cercariae shed. series i snails wer ... | 1986 | 3819965 |
| genetics of biomphalaria glabrata: linkage analysis of genes for pigmentation, enzymes, and resistance to schistosoma mansoni. | the snail, biomphalaria glabrata, is a major intermediate host of the human blood fluke, schistosoma mansoni, in the americas. the inheritance and linkage relationships of a gene enabling adult snails to resist infection by a puerto rican strain of the parasite were analyzed using two laboratory stocks that differed in susceptibility, pigmentation, and five electrophoretically detectable enzyme markers. segregation ratios in second-generation intraspecific hybrids between susceptible (m-stock) a ... | 1985 | 3866575 |
| assessment of schistosomiasis in the dominican republic. | active transmission of intestinal schistosomiasis is currently limited to the southeastern part of the dominican republic. a population-based stool survey in 1980 detected 4 asymptomatic individuals among 114 selected at random in 2 towns and a rural community in el seibo province. the distribution of the transmitting snail, biomphalaria glabrata, considerably exceeds that of schistosoma mansoni, extending to the national district and capital city of santo domingo and well into certain central v ... | 1985 | 3931167 |
| isolation and partial characterization of shared antigens of biomphalaria glabrata and schistosoma mansoni and their evaluation by the elisa and the eitb. | serum from humans infected with schistosoma mansoni, when reacted with a biomphalaria glabrata soluble hepatopancreas antigen extract (bgsha) yields 2 lines of precipitation by gel diffusion and 1 by immunoelectrophoresis. the igg from the serum of a human infected with s. mansoni was coupled to cnbr-activated sepharose 4b. bgsha (8.0 mg) was then filtered through the gel and the bound antigens, denoted bgsm, eluted with hcl-glycine, ph 2.6. these bound antigens comprised 2.8% of the total bgsha ... | 1985 | 3932633 |
| lectin-dependent cell-mediated cytotoxicity in an invertebrate model: con a does not act as a bridge. | the plant lectin concanavalin a (con a) has been used in an invertebrate model of lectin-dependent cell-mediated cytotoxicity (ldcc). macrophage-like cells from the susceptible host snail biomphalaria glabrata become cytotoxic effectors when they encounter sporocysts of the parasitic trematode schistosoma mansoni that have been treated with con a. the sugar alpha-methyl mannoside and rabbit anti-con a antibodies fail to block this ldcc. con a is effective only when the target, not the effector c ... | 1986 | 3949370 |
| biomphalaria glabrata (gastropoda): effect of urethane on the morphology and function of hemocytes, and on susceptibility to schistosoma mansoni (trematoda). | 1985 | 3998486 |