Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| changes in plasma opsonization of yeast after isolation of biomphalaria glabrata in small volumes of water. | 1989 | 2768831 | |
| 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 |
| [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 |
| 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 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| comparison of starvation and infection by schistosoma mansoni on tissue viability and the 31p nmr spectrum of biomphalaria glabrata. | 1986 | 3716546 | |
| 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 |
| 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 |
| [factors responsible for preventing the carrying out of the schistosoma mansoni cycle in the waters of grande terre of guadeloupe (french antilles)]. | different surveys which have been conducted in ponds and pools in the grande terre of guadalupe, have demonstrated the absence of schistosoma mansoni transmission in spite of apparent favourable ecological conditions. four hypothesises can explain this absence of transmission: 1 - the presence of biomphalaria glabrata populations non-susceptible to the infestation by s. mansoni. 2 - ecological conditions unfavourable to the survival of parasitized snails. 3 - ecological conditions unfavourable t ... | 1985 | 4004031 |
| biomphalaria glabrata in haiti. | biomphalaria glabrata, an intermediate host for schistosoma mansoni, was first reported in haiti in 1891 at one location in the départment du nord and in 1977 it was reported at several sites in one additional watershed. our study identifies two additional locations each on a different watershed plus a third possible site. a wide but discontinuous distribution of the snail on the north coast of haiti is confirmed (no autochthonous infections with s. mansoni have been reported). while there are m ... | 1985 | 4082255 |
| [resistance of biomphalaria schrammi of arcos, minas gerais, brazil, to infection with 2 strains of schistosoma mansoni]. | the descendants of planorbid snail biomphalaria schrammi crosse, 1864, collected in the region of arcos, state of minas gerais, brazil, were exposed to miracidia of two strains of schistosoma mansoni: the "le" strain from belo horizonte, minas gerais state and the "sj" strain from são josé dos campos, state of são paulo. of the 172 snails exposed to miracidia of both strains, none were infected. on the other hand, 100 biomphalaria glabrata snails of the control group showed infection rates of 88 ... | 1985 | 4088045 |
| [a stock of infected snails for the mass breeding of cercariae and schistosomules]. | a routine to maintain infected snails biomphalaria glabrata able to produce 1-2 million cercariae per week and a mean shedding of about 3,500 cercariae per snail was quantitatively described. to a monthly production of about 5.3 and 6.5 million cercariae during the years of 1982 and 1983 it was necessary to expose an average of 1,557 and 1,957 snails, respectively. the efficiency described was maintained by infecting 2,000 snails per month (infectivity index of about 60%). a maximal production o ... | 1985 | 4088046 |
| orientation to light of juvenile and adult forms of melanic and albino populations of biomphalaria glabrata(say, 1818). | 1985 | 4088040 | |
| 31p nmr studies on adenylates and other phosphorus metabolites in the schistosome vector biomphalaria glabrata. | 31p nuclear magnetic resonance spectroscopy was applied successfully to whole intact and de-shelled snails and to the isolated digestive gland-gonad tissue complex as well as other tissues of biomphalaria glabrata. several phosphorus metabolites, including atp and adp, were observed. the mean atp/adp ratio calculated for the tissue complex was 3.1 and the atp concentration was 0.73 nmoles/mg tissue fresh weight. assignments for amp, sugar phosphates, and inorganic phosphate peaks were tentativel ... | 1985 | 4057009 |
| 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 |
| 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 |
| biomphalaria glabrata (gastropoda): effect of urethane on the morphology and function of hemocytes, and on susceptibility to schistosoma mansoni (trematoda). | 1985 | 3998486 | |
| schistosoma mansoni: lectin-dependent cytotoxicity of hemocytes from susceptible host snails, biomphalaria glabrata. | normally benign hemocytes from a strain (m-line) of the snail, biomphalaria glabrata, susceptible to schistosoma mansoni, became cytotoxic toward the sporocyst stage if the parasite was first treated with the lectin, concanavalin a. concanavalin a binding was inhibitable with alpha-methyl mannoside and killing was dose-dependent. maximal levels of concanavalin a-induced cytotoxicity were comparable with levels observed when hemocytes from a resistant snail strain (13-16-r1) encountered untreated ... | 1985 | 4040473 |
| plasma components which mediate cellular defences in the gastropod mollusc biomphalaria glabrata. | blood plasmas from certain strains of biomphalaria glabrata are known to have components which facilitate a hemocyte-effected cytotoxic response against encapsulated schistosoma mansoni sporocysts. the possible identity of the factor(s) has been investigated. sporocysts placed in snail plasma rapidly acquire a wide variety of host plasma antigens, at least some of which are displayed on the parasite surface. plasmas from strains of snail resistant to the parasite agglutinate fixed sporocysts, wh ... | 1985 | 4043487 |
| 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 |
| 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 |
| [selection of genotypes of schistosoma mansoni and their maintenance by sporocyst transplantation]. | schistosoma mansoni was isolated by hatching eggs obtained from a naturally infected rat in grand etang, guadeloupe; fifty biomphalaria glabrata were exposed to five miracidia each. the resulting cercariae were used to infect laboratory mice which were later sacrificed to provide worms for enzyme analyses and eggs for further infections. seven enzymes in extracts of individual worms were examined by isoelectric focusing in polyacrylamide gels: acp, g6pdh, pgm, gpi and hk showed no variation, whe ... | 1984 | 6437612 |
| comparison of the rhythmic emergence of schistosoma mansoni cercariae from biomphalaria glabrata in different lighting regimens. | 1984 | 6541689 | |
| [activities of a schistosoma mansoni focus of transmission in martinique (french antilles)]. | a focus of intestinal schistosomiasis was discovered in november 1981 in martinique in the saint-pierre area. an analysis of its structure and of the mecanisms of the transmission of the parasite was carried out between 1981 and 1983. this focus presents the following particularities: a transmission site very small constituted by water cress beds; a small human population infected with a prevalence of 13% (positive stools) to 41,3% (positive serologies); a weak fecal contamination of the water; ... | 1984 | 6524823 |
| schistosoma mansoni: passive transfer of resistance by serum in the vector snail, biomphalaria glabrata. | passive transfer of natural resistance to schistosoma mansoni (pr-1 strain) has been successfully accomplished in the snail intermediate host, biomphalaria glabrata (pr albino, m-line strain). injection of serum (cell-free hemolymph) from a naturally schistosome-resistant strain of b. glabrata (10-r2) into pr albino snails induced a complete protection from a primary infection with the parasite in 29 of 48 snails (60.4%). in comparison, inoculation of homologous pr albino serum or heterologous p ... | 1984 | 6479289 |
| the adenylate nucleotide pool in the digestive gland-gonad complex of biomphalaria glabrata infected by schistosoma mansoni. | the levels of adenylate nucleotides were examined in the digestive gland and ovotestes of biomphalaria glabrata during cercarial shedding of schistosoma mansoni, 10 weeks post-infection. in general, parasitization resulted in decreases in the adenylate levels in both tissues, but the results were not statistically significant. moreover, the energy charge ratio was not significantly altered. the mean energy charge in ovotestes from uninfected and infected individuals was 0.81 and 0.77, respective ... | 1984 | 6527694 |
| role of cellular and humoral components in the encapsulation response of biomphalaria glabrata to schistosoma mansoni sporocysts in vitro. | 1984 | 6483876 | |
| isolation, characterization and functional assessment of a hemagglutinin from the plasma of biomphalaria glabrata, intermediate host of schistosoma mansoni. | an agglutinin from the plasma of biomphalaria glabrata, vector of schistosoma mansoni, has been isolated and partially characterized. its isolation is a simple two-step process, yielding an essentially pure preparation that can then be manipulated free from other plasma components. it is a large glycoprotein (10(6) daltons), found in four of the five snail strains tested, and possesses affinity for galactose-type sugar residues. based upon criteria such as molecular weight, carbohydrate and eryt ... | 1984 | 6500135 |
| chronobiological aspects of the host-parasite relationships between biomphalaria glabrata and schistosoma mansoni: cercarial production and infectivity, and growth kinetics of the host. | 1984 | 6501917 | |
| [new foci of transmission of schistosoma mansoni in the state of pará]. | two new foci of transmission of schistosoma mansoni in the state of pará are recorded, with the finding of naturally infected biomphalaria glabrata in the municipalities of viseu and belém. uninfected specimens of biomphalaria straminea, as well as the planorbid species biomphalaria schrammi, drepanotrema lucidum and d. anatinum, were found in the same area. | 1984 | 6535922 |
| immune-recognition of schistosoma mansoni primary sporocysts may require specific receptors on biomphalaria glabrata hemocytes. | cellular interactions, leading to cell-mediated cytotoxicity when biomphalaria glabrata hemocytes encapsulate schistosoma mansoni sporocysts, have been investigated. rabbit antibodies (igg), when bound to antigens on sporocyst surfaces, prevent the normal cytoadherence (ca) of hemocytes from both susceptible and resistant host snails. since interference with ca occurs with even fixed sporocysts, the effect is not due to igg stimulated modulation of the parasite surface. using two antisera with s ... | 1984 | 6240624 |
| experimental studies of age-prevalence curves for schistosoma mansoni infections in populations of biomphalaria glabrata. | we report the results of experimental studies of the generation of age-prevalence curves for schistosoma mansoni infections in laboratory populations of biomphalaria glabrata. within snail populations of varying sizes and age structures, the net force of infection is shown to be linearly dependent on the rate at which miracidia are introduced into the aquatic habitat of the host. for individual snails, the per capita force of infection is shown to be related to snail age and size, and the death ... | 1984 | 6472887 |
| intergeneric reproductive stimulation and parthenogenesis in schistosoma mansoni. | when mice were infected with female cercariae of schistosoma mansoni and male cercariae of schistosomatium douthitti, many mixed pairs formed. the paired females were approximately the same size as those in unisexual infections, far smaller than females paired with s. mansoni males. although the sch. douthitti males possessed well-developed testes, sperm were not found in their female partners, which developed scanty vitelline glands and produced laterally spined eggs typical of s. mansoni. such ... | 1984 | 6504564 |
| an ultrastructural study of the effect of parasitism by larval schistosoma mansoni on the calcium reserves of the host, biomphalaria glabrata. | the tissues of biomphalaria glabrata contain three types of calcium cells which can be differentiated by their location and the size and number of their contained corpuscles. x-ray analysis has confirmed the presence of calcium and magnesium in the corpuscles. molluscs containing the larval stages of schistosoma mansoni at 40 days post infection show disintegration of the calcareous corpuscles in type-a calcium cells and erosion of the inner surface of the shell. | 1984 | 6467339 |
| schistosoma mansoni: long-term maintenance of clones by microsurgical transplantation of sporocysts. | schistosoma mansoni sporocysts originally derived from monomiracidially infected biomphalaria glabrata snails were serially transplanted into the cephalopedal sinus of anesthetized snails by the microsurgical implantation of fragments of parasitized hepatopancreas and ovotestis. three to six passages each of five male and five female clones were maintained for as long as 2.0 years. of the recipient snails which survived surgery, 87% released cercariae, usually beginning 5-7 weeks after surgery. ... | 1984 | 6692880 |
| schistosoma mansoni: agglutination of sporocysts, and formation of gels on miracidia transforming in plasma of biomphalaria glabrata. | the resistance or susceptibility of biomphalaria glabrata strains to strains of schistosoma mansoni, the human blood fluke, are evidenced by the responses of snail hemocytes to sporocysts of the schistosome, both in vivo and in vitro. it is now reported that living sporocysts of the pr1 strain of s. mansoni agglutinate in the plasma of all tested strains of b. glabrata, in contrast to fixed sporocysts which agglutinate only in plasma from resistant snail strains. the agglutinating activity in re ... | 1984 | 6745386 |
| [chemoprophylaxis of schistosomiasis: molluscacidal activity of natural products--assays with adult snails and oviposition]. | data concerning the molluscicidal activity of 159 extracts from 84 brazilian plants on biomphalaria glabrata, the most important intermediate host of schistosoma mansoni in brazil, are presented. seventy eight extracts (49,0%) showed activity against snails or eggs, but only twenty nine (18.2%) were active on both, snails and eggs. extracts of two species (mikania hirsutissima and qualea multiflora) have shown to be lethals to adult snails at 10 ppm concentration. | 1984 | 6548884 |
| [experimental schistosomiasis iii. observations on the infestation of biomphalaria glabrata by a miracidium of schistosoma mansoni]. | 380 b. glabrata infected with 1 miracidium of s. mansoni produced 87 positive snails (22,9%), 38 of which sending out male cercariae and 49 female cercariae. the snails belonged to 3 experimental series kept at 27 degrees and 24 degrees c for 15 weeks under continuous lighting. there was no difference between the proportions of both sexes. the survival of the positive snails was favoured by the male sex. the shedding of female cercariae was greater than shedding of male. during those 15 weeks, t ... | 1984 | 6721371 |
| [experimental infection of biomphalaria glabrata with schistosoma mansoni by the injection of miracidia]. | 1983 | 6672864 | |
| altered feeding response as a cause for the altered heartbeat rate and locomotor activity of schistosoma mansoni-infected biomphalaria glabrata. | biomphalaria glabrata infected with schistosoma mansoni for 33 days fed more often than uninfected snails. whereas uninfected snails had nocturnal increases in feeding, snails with a 33-day-old infection of s. mansoni fed as often during the day as in the night. using direct observation and film analysis, we found that feeding increased the heartbeat rate and locomotor activity of b. glabrata. when snails were allowed to feed ad lib., infected snails had higher heartbeat rates than uninfected sn ... | 1983 | 6631636 |
| effects of alterations in the heartbeat rate and locomotor activity of schistosoma mansoni-infected biomphalaria glabrata on cercarial emergence. | during a 27-hr period of food deprivation, biomphalaria glabrata infected with schistosoma mansoni had lower heartbeat rates and locomotor activities than did controls that were feeding ad lib. however, there was no difference between the cercarial emergence from control and experimental snails either before, during, or after the period of food deprivation. no correlation was found between the locomotor activity of the snail and the number of cercariae emerging from the snail in continuous light ... | 1983 | 6631637 |
| lysosomal enzyme activities in susceptible and refractory strains of biomphalaria glabrata during the course of infection with schistosoma mansoni. | the distribution and abundance of the lysosomal enzyme markers, acid phosphatase (ap), peroxidase (po), and nonspecific esterase (ne), within circulating blood cells (hemocytes) were examined in a schistosome-susceptible (pr albino m-line) and a resistant (10-r2) strain of biomphalaria glabrata during the course of infection with schistosoma mansoni. the dynamics of serum (cell-free hemolymph) ap activities and total hemocyte numbers in infected snails also were investigated. hemocyte subpopulat ... | 1983 | 6674450 |
| schistosoma mansoni: immunofluorescent detection of its antigen reacting with biomphalaria glabrata amoebocytes. | the reaction of amoebocytes in the hemolymph of the infected intermediate host, biomphalaria glabrata, to schistosoma mansoni antigens has been investigated using the indirect immunofluorescence antibody test. monolayers of amoebocytes, prepared from hemolymph of infected and normal snails, were first fixed and then reacted with antisera obtained from mice infected for 7 to 9 weeks. nonspecific and cross-reactions between the antisera and monolayers of amoebocytes were eliminated by absorbing th ... | 1983 | 6337058 |
| schistosoma mansoni and biomphalaria glabrata share epitopes: antibodies to sporocysts bind host snail hemocytes. | 1983 | 6195272 | |
| mimicry of snail host antigens by miracidia and primary sporocysts of schistosoma mansoni. | polyvalent antisera generated in rabbits to soluble haemolymph components from schistosoma mansoni-susceptible (pr albino 'm line') and s. mansoni-resistant (10-r2) stocks of the snail biomphalaria glabrata were employed as membrane probes to determine if antigens related to snail haemolymph were produced by the early larval stages of s. mansoni (pr-1 strain). using immunofluorescence and immunoelectron microscopical methods we have demonstrated that antibodies to susceptible (anti-suscept) and ... | 1983 | 6191268 |
| purine metabolism in biomphalaria glabrata under starvation and infection with schistosoma mansoni. | purine content and its alterations during a starvation period of 29 days and an infection period of 52 days were studied. during starvation the amount of uric acid increased from 2.11 +/- 0.95 mg/g dry wt in control snails to a maximum of 6.73 +/- 3.99 mg/g dry wt on day 29 of starvation for uric acid and from 4.73 +/- 2.10 mg/g dry wt in control snails to a maximum of 11.29 +/- 3.48 mg/g dry wt on day 23 of starvation for guanine. during infection there was an increase with both uric acid and g ... | 1983 | 6641159 |
| laboratory comparison of the relative success of biomphalaria glabrata stocks which are susceptible and insusceptible to infection with schistosoma mansoni. | a method of interrupting the life-cycle of the human blood fluke schistosoma by increasing the proportion of genetically insusceptible intermediate host snails in natural populations was first proposed nearly 25 years ago. the method assumes that insusceptible snails will be at a selective advantage over susceptible snails when the schistosome parasite is present, and therefore natural selection will act to increase the proportion of alleles for insusceptibility. a major objection to the propose ... | 1983 | 6856336 |