| [evaluation of 10 years of research on s. mansoni schistosomiasis a in the french west indies]. | from 1971 until 1982, we studied the ecological factors which stead fast a perennial schistosomiasis in guadeloupe on an exhaustive mode. more recently, we start a similar investigation in martinique. in guadeloupe the single vector of schistosoma mansoni is the snail biomphalaria glabrata which is an ubiquist species. but the transmission to man is restricted to the "canal-sewers" where faeces are dropped and not in the rivers of basse-terre or the ponds of grande-terre. moreover, the infection ... | 1982 | 7126776 |
| amebocytic accumulations in biomphalaria glabrata: fine structure. | internal pathologic conditions in four stocks of biomphalaria glabrata involve amebocytes. most snails exhibiting these conditions are also nonsusceptible to infection with schistosoma mansoni. fine structure studies reveal that periaortic and atrial amebocytic accumulations show two responses that involve heart tissue: a generalized response in which amebocytes have infiltrated the myocardium and focal areas of nodules in which heart tissue is encapsulated and destroyed. in pericardial accumula ... | 1982 | 7128891 |
| transmission of schistosoma mansoni from man to snail: laboratory studies on the influence of snail and miracidial densities on transmission success. | the relationship between infection success, the density of schistosoma mansoni miracidia and the density of the snail host biomphalaria glabrata was examined experimentally. within laboratory infection arenas, the distribution of miracidial infections/snail was approximately uniform and the net rate of snail infection was directly positive binomial to miracidial density. in contrast, however, the rate of infection declined exponentially as snail density increased. mathematical models are develop ... | 1982 | 7145477 |
| effects of starvation and infection with schistosoma mansoni on the release rate of free amino acids (faa) by biomphalaria glabrata. | 1. the elimination of dissolved free amino acids (faa) by individual snails during a period of 2 hr was measured. the faa concentration in the hemolymph and in the homogenate also was determined. 2. for uninfected, normally fed snails a daily faa production of 0.7 +/- 0.25 mumol glycine equivalents/g live wt was found. with snails starving for 7 days the daily faa release rate fell to a mean value of 0.44 +/- 0.19 mumol glycine equivalents/g live wt. infection with schistosoma mansoni, however, ... | 1982 | 7172633 |
| use of praziquantel in patients with schistosomiasis mansoni previously treated with oxamniquine and/or hycanthone: resistance of schistosoma mansoni to schistosomicidal agents. | fourteen patients with active schistosomiasis mansoni in spite of previous treatment with oxamniquine and/or hycanthone were treated with praziquantel, single oral dose of 45 to 50 mg/kg body-weight. all underwent clinical, laboratory and electrocardiographic examination before and after treatment. untoward effects (dizziness, drowziness, nausea and abdominal pain) were observed in ten. laboratory findings disclosed no significant alteration and the electrocardiograms showed no abnormalities. mo ... | 1982 | 7179419 |
| [comparative study of the susceptibility of biomphalaria glabrata populations of belo horizonte (mg), to schistosoma mansoni infection and to molluscacides]. | | 1982 | 7182912 |
| resistance to schistosome infection in biomphalaria glabrata induced by gamma radiation. | | 1981 | 7196934 |
| experimental epidemiology of schistosomiasis. ii. prepatency of schistosoma mansoni in biomphalaria glabrata at diurnally fluctuating temperatures. | the basic hyperbolic relationship established between constant water temperatures and the length of the prepatent period in the snail was tested as diurnally fluctuating temperatures, stimulating natural conditions. diurnal temperature variations are generally summed up by s. mansoni according to the time-temperature product and are independent of the shape of the temperature curve. using a simple hyperbolic formula, the time of prepatency can be calculated for temperatures ranging from 16 degre ... | 1981 | 7198850 |
| [life cycle of clinostomum golvani n. sp. (trematoda : clinostomidae) a larval parasite of biomphalaria glabrata, the snail vector of schistosoma mansoni in guadeloupe (author's transl)]. | the life cycle of a new species of clinostomidae, clinostomum golvani, described in guadeloupe (french west indies). the first intermediate host is the snail vector of schistosoma mansoni in this island, biomphalaria glabrata, which can be sterilized by this parasite. poecilia reticulata (guppy) serves as the second intermediate host. adult worms were obtained under experimental conditions from butorides virescens (the definitive host in nature), nycticorax nycticorax and ardea purpurea. the adu ... | 1980 | 7224533 |
| dynamics of larval populations of schistosoma mansoni in biomphalaria glabrata. i rhythmic production of cercariae in monomiracidial infections. | | 1981 | 7271357 |
| schistosoma mansoni, nih-sm-pr-2 strain, in susceptible and nonsusceptible stocks of biomphalaria glabrata: comparative histology. | of 10 inbred stocks of biomphalaria glabrata examined, eight were susceptible to the nih-sm-pr-1 strain (pr-1) of schistosoma mansoni, whereas only three were susceptible to the nih-sm-pr-2 strain (pr-2). by employing a histological ranking system based on parasite development and host tissue response, we have observed a range of nonsusceptibility among stocks nonsusceptible to pr-2. in three nonsusceptible stocks, sporocysts were rapidly surrounded by host amebocytes and were destroyed within a ... | 1981 | 7299581 |
| [contribution to the study of nervous system in larval and adult forms of schistosoma mansoni sambon, 1907 (trematoda digenea). ii. role of serotonine and dopamine (author's transl)]. | this study provides details concerning the localization and role of 5-ht and da in schistosoma: 1) 3h-5ht is incorporated selectively by the nerve fibers containing dense granules measuring 820 +/- 20 a (type 2 granules), combined at times with other structures; the presence of "cold" dopamine in the environment does not alter the incorporation; 2) 3h-da is also incorporated in vitro by the nerve fibers and occasionally by the muscle fibers of the adult schistosoma; 3) neither the intraovular mi ... | 1981 | 7316398 |
| dynamics of larval populations of schistosoma mansoni in biomphalaria glabrata ii. chronobiology of the intramolluscal larval development during the shedding period. | | 1981 | 7316580 |
| schistosoma mansoni: effect on growth, fertility, and development of distal male organs in biomphalaria glabrata exposed to miracidia at different ages. | growth, egg laying rate, and mortality of biomphalaria glabrata (portorican strain), maintained in groups of two, after exposure at different ages (1, 2, 4, 6, 8 weeks) to three miracidia each of schistosoma mansoni (liberian strain) were determined. the findings in infected snails were compared with those in exposed but uninfected (negative) and in unexposed snails. younger snails were infected at higher rates, and these showed a significantly increased mortality. young infected snails grew muc ... | 1981 | 7324545 |
| selective interference with granulocyte function induced by echinostoma paraensei (trematoda) larvae in biomphalaria glabrata (mollusca). | various trematode larvae can interfere with the host snail's resistance to the same or unrelated trematode species, chiefly, it appears by interference with the function of the host's granulocytes. in biomphalaria glabrata infected with the trematodes, echinostoma paraensei, granulocytes lose their ability to encapsulate the larvae of trematodes to which the hosts were previously resistant. however, the granulocytes in these snails retain their ability to encapsulate injected latex spheres, or l ... | 1981 | 7328451 |
| reduction in transmission of schistosoma mansoni by a four-year focal mollusciciding programme against biomphalaria glabrata in saint lucia. | the effect of transmission of schistosoma mansoni of a focal snail control programme was investigated over four years amongst approximately 1250 people living in five communities in the steep-sided soufriere river valley, st. lucia, west indies. bayer 6076 was applied from constant flow drip cans to 12 stream sections at a target dose of 8 mg/litre clonitralide every four weeks. only proven and potential transmission sites were treated; marsh habitats, where biomphalaria glabrata were widespread ... | 1981 | 7330940 |
| [evolution of spopocysts of schistosoma mansoni sambon 1907 in biomphalaria glabrata (say 1818) and biomphalaria tenagophila (d'orbigny 1835)]. | | 1981 | 7336119 |
| [susceptibility to schistosoma mansoni infection of biomphalaria glabrata and biomphalaria tenagophila in the federal district, brazil]. | | 1981 | 7345560 |
| therapeutic efficacy of oral oxamniquine in the toxemic form of schistosomiasis mansoni: treatment of eleven individuals from two families, and experimental study. | two families, comprising 11 individuals in the toxemic form of schistosomiasis mansoni, infected in belo horizonte, brazil were treated. parasitological cure was obtained in 5 (45%) of the patients after a single oral dose of oxamniquine (mansil), 20 mg/kg body weight. no significant side effects were observed. to evaluate the possibility of resistance to the drug, cercariae collected from biomphalaria glabrata infected with micracidia from eggs obtained from three of the individuals not cured w ... | 1980 | 7352627 |
| the destruction of schistosoma mansoni mother sporocysts in vitro by amoebae isolated from biomphalaria glabrata: an ultrastructural study. | | 1980 | 7365267 |
| differential leukocytic responses of biomphalaria glabrata to infection with schistosoma mansoni. | | 1980 | 7365270 |
| biomphalaria glabrata amoebocytes: effect of schistosoma mansoni infection on in vitro phagocytosis. | | 1980 | 7373069 |
| macrophagelike hemocytes of resistant biomphalaria glabrata are cytotoxic for sporocysts of schistosoma mansoni in vitro. | when schistosoma mansoni miracidia penetrate resistant individuals of the intermediate host snail biomphalaria glabrata, the sporocyst is encapsulated by hemocytes (macrophagelike cells of the snail circulation) and killed. in our in vitro model the same fate requires only sporocysts and snail hemolymph. however, when cultured in plasma alone (cell-free hemolymph), sporocysts remain viable for more than 3 days, regardless of whether the plasma is from susceptible or resistant snails. when hemoly ... | 1980 | 7391885 |
| inducement of miracidia-immobilizing substance in the hemolymph of biomphalaria glabrata. | | 1980 | 7409973 |
| schistosoma mansoni: cytotoxicity of hemocytes from susceptible snail hosts for sporocysts in plasma from resistant biomphalaria glabrata. | | 1980 | 7428914 |
| [biological competition between biomphalaria glabrata (say, 1818) and biomphalaria tenagophila (d'orbigny, 1835), in natural breeding areas in the municipality of ourinhos, s.p. (brazil)]. | | 1980 | 7433874 |
| tissue reactions induced by schistosoma mansoni in biomphalaria glabrata. | in biomphalaria glabrata with a strong natural resistance, schistosoma mansoni sporocysts are rapidly encapsulated by granulocytes and killed, mainly by the strong phagocytic activity of the cells. irradiated echinostoma paraensei sporocysts seem able to suppress the function of the granulocytes. tissue reactions in snails with self-cure demonstrate: involvement of two types of cells, granulocytes and hyalinocyte-like cells; formation of amoeba-fibrous capsules; limited tendency of granulocytes ... | 1980 | 7436601 |
| abnormal development of the digestive gland in biomphalaria glabrata. | | 1980 | 7440998 |
| schistosoma mansoni control in cul de sac valley, saint lucia. i. a two-year focal surveillance-mollusciciding programme for the control of biomphalaria glabrata. | an area-wide mollusciciding campaign in cul de sac valley, st. lucia reduced incidence of schistosoma mansoni from 22% to 4.3% between 1970 and 1975. following this, a two-year focal surveillance-mollusciciding programme was introduced. sites of potential transmission of s. mansoni were identified and routinely searched for biomphalaria glabrata. if found, the site was treated with clonitralide 25% emulsifiable concentrate. two chemotherapy campaigns supplemented the snail control programme. as ... | 1980 | 7445045 |
| the boqueron project after 5 years: a prospective community-based study of infection with schistosoma mansoni in puerto rico. | the boqueron schistosomiasis project is a prospective community-based study of schistosoma mansoni infection after the interruption of transmission by nonchemotherapeutic control measures. the study methods and the parasitologic results of the first five annual stool surveys are described in this report. in the first year, 1972, among 904 inhabitants (88% of the total population) the prevalence of infection was 40%, and the geometric mean intensity of infection among positives was 16.1 eggs per ... | 1980 | 7446813 |
| metabolic interrelationship of parasitic trematodes and molluscs, especially schistosoma mansoni in biomphalaria glabrata. | | 1980 | 7456639 |
| [cellular immunity in mollusk hosts of schistosomes. primary results regarding biomphalaria glabrata]. | cell culture are obtained from the saccular part of the kidney of biomphalaria glabrata in a medium derived from schneider drosophilia medium. two types of cells migrate from the explant: numerous amoebocytes and some fibroblasts. migration of amoebocytes appears to be regular. these amoebocytes are able to encapsulate and destroy particules and dead miracidiums. amoebocytes from incompatible snails rapidly surround miracidiums and early larvae (primary sporocysts) whereas compatible miracidium ... | 1980 | 7460123 |
| production of schistosoma mansoni daughter sporocysts from mother sporocysts maintained in synxenic culture with biomphalaria glabrata embryonic (bge) cells. | in vitro production of schistosoma mansoni daughter sporocysts (ds) from miracidium-derived mother sporocysts (ms) was achieved by synxenic larval cultivation with cells of the biomphalaria glabrata embryonic (bge) cell line. the in vitro growth and viability of ms cocultured with bge cells or in bge cell-conditioned medium were significantly extended beyond that of larvae cultured in fresh medium alone. however, complete ds development and emergence from ms were achieved only in the presence of ... | 1995 | 7472861 |
| killing of schistosoma mansoni sporocysts in biomphalaria glabrata implanted with amoebocyte-producing organ allografts from resistant snails. | schistosome-susceptible national institutes of health (nih) albino biomphalaria glabrata were implanted with the amoebocyte-producing organ (apo) from 4 types of donors: (1) exposed-resistant (er), i.e., schistosome-resistant 13-16-r1 snails that had been exposed to miracidia of schistosoma mansoni 30 or more days previously in order to verify their resistance, (2) exposed-susceptible (es), i.e., nih albino snails that had been similarly exposed to miracidia, (3) unexposed-resistant (ur), and (4 ... | 1995 | 7472893 |
| schistosoma mansoni: excretory-secretory polypeptides exhibit selective binding to plasma components of the snail biomphalaria glabrata. | previous studies have shown that schistosoma mansoni excretory-secretory polypeptides (esp) inhibit various internal defense functions of hemocytes from biomphalaria glabrata and that plasma also may exert a modulatory effect on hemocyte activity. to better understand how plasma may influence hemocyte-schistosome interactions in inbred strains of snails, biotinylated esp (b-esp) were used as probes to identify esp-reactive plasma components and partially characterize the nature of their binding ... | 1995 | 7498426 |
| invertebrate host-parasite relationships: convergent evolution of a tropomyosin epitope between schistosoma sp., fasciola hepatica, and certain pulmonate snails. | monoclonal antibodies (mab) directed against schistosoma mansoni tropomyosin isoform, smtm (xu et al. experimental parasitology 69, 373-392, 1989), were used to test for cross-reactivity with biomphalaria glabrata antigens. one mab (1f10) recognized antigens of 39, 41, and 80 kda in a snail head/foot antigen preparation but not a hepatopancreas antigen preparation. another mab (1c1) cross-reacted with a 39-kda antigen in the head/foot extract but not in the hepatopancreas extract. epitope mappin ... | 1994 | 7512930 |
| [susceptibility of biomphalaria tenagophila and biomphalaria glabrata from a same region to 2 schistosoma mansoni strains]. | b. tenagophila snails from ouro branco, mg, showed positivity for s. mansoni, with infection rates of 5%, 10%, (sj strain), and 1% (le strain) using a pool of miracidia. the mollusks were found to be susceptive from the 3rd generation reared in laboratory onwards. the b. tenagophila (ob, mg) when individually exposed to 10 miracidia, showed infection rate of 2% for le strain. b. glabrata snails from gagé, mg, showed a positivity rate of 58% for s. mansoni (le strain), under experimental conditio ... | 1994 | 7569607 |
| production of schistosoma mansoni cercariae by biomphalaria glabrata from a focus in belo horizonte, minas gerais. | the snail density, levels of infection and the monthly production of schistosoma mansoni cercariae by biomphalaria glabrata were determined in a focus of barreiro de baixo (belo horizonte, mg, brazil). during a period of 38 months (1984 to 1987) 5,366 snails were collected of which 324 (6.03%) were infected with s. mansoni. the total number of cercariae shed was 5,667,312. each snail shed an average of 17,422 cercariae during the time that it was under study in the laboratory. the greatest longe ... | 1994 | 7569620 |
| distribution of schistosome genetic diversity within molluscan intermediate hosts. | naturally infected biomphalaria glabrata snails were collected at two sites near belo horizonte, brazil, and schistosoma mansoni cercariae isolated from single snails were used to infect individual mice. genetic comparison of single worm dna was accomplished by hybridization of southern blots to a polymorphic repetitive dna element. genetic profiles of parasite individuals revealed a diverse array of parasite genotypes in naturally infected intermediate hosts. the observed distribution of schist ... | 1995 | 7675537 |
| schistosoma mansoni: comparison of cloned tropomyosin antigens shared between adult parasites and biomphalaria glabrata. | rabbit antisera, raised against whole, homogenized hepatopancreas from uninfected biomphalaria glabrata, were used to screen a cdna library prepared from adult schistosoma mansoni. of 1.8 x 10(5) recombinants screened, 34 clones were specifically immunoreactive with the antisera. twenty of the clones were subcloned for further analysis, and 13 of the 20 were demonstrated to hybridize to a cdna probe encoding schistosome tropomyosin i (psmtm) at high stringency (xu et al. experimental parasitolog ... | 1993 | 7685709 |
| hemocytes of schistosome-resistant and -susceptible biomphalaria glabrata recognize different antigens on the surface of schistosoma mansoni sporocysts. | a cytoadherence assay was used to determine whether antibodies to plasma and hemocyte components of schistosoma mansoni-susceptible (m-line) and -resistant (10-r2, 13-16-r1) strains of biomphalaria glabrata affected attachment of hemocytes to chemically fixed schistosome sporocysts differentially. experiments used purified, intact igg and purified fab fragments of each antibody. indirect fluorescent antibody tests confirmed that the intact purified igg to plasma and hemocytes from the 3 strains ... | 1995 | 7707192 |
| spatial distribution patterns of the sporocyst infrapopulation of schistosoma mansoni within its mollusc host (biomphalaria glabrata): an unusual phenotype of aggregation. | a study carried out on the intramolluscan development of the larval stages of schistosoma mansoni from venezuela in its intermediate host biomphalaria glabrata shows the existence of 2 patterns for the spatial distribution of daughter sporocysts within the digestive gland of the snail. besides the normal pattern, which is a random distribution of daughter sporocysts within the gland, 11% of the infected snails harbored an infection phenotype with daughter sporocysts strongly aggregated in only t ... | 1995 | 7707215 |
| studies on host-parasite relationship between the puerto rican strain of schistosoma mansoni and biomphalaria snails. | immunoelectrophoretic studies on common antigenicities were carried out by using rabbits sera immunized with the puerto rican strain of schistosoma mansoni adult worms or eggs and antigens of several adult biomphalaria snails and vice versa. as the result, s. mansoni adult worm extracts produced 8 bands both with extracts of biomphalaria glabrata pigmentation and b. glabrata pigmentado, 3 to 4 bands with those of b. glabrata albino and 1 to 2 bands with those of b. straminea. on the other hand, ... | 1994 | 7777917 |
| schistosomicidal activities of lymnaea stagnalis haemocytes: the role of oxygen radicals. | macrophage-like defence cells (haemocytes) of the pond snail lymnaea stagnalis mediate cytotoxicity through reactive oxygen intermediates (rois). this activity is nadph-oxidase dependent, as in mammalian phagocytes during the respiratory burst. in this study, mother sporocysts of schistosomes, the compatible trichobilharzia ocellata and the incompatible schistosoma mansoni evoke in vitro roi activities (detected by luminol dependent chemiluminescence, ldcl) from l. stagnalis haemocytes. s. manso ... | 1994 | 7800416 |
| schistosoma mansoni: interleukin-1 increases phagocytosis and superoxide production by hemocytes and decreases output of cercariae in schistosome-susceptible biomphalaria glabrata. | decreases in the number of schistosoma mansoni cercariae released from susceptible m-line biomphalaria glabrata were detected following injection with the recombinant human cytokine, interleukin-1. no differences in either the time post-exposure at which shedding began or the percentage of snails shedding cercariae were detected between interleukin-1 injected, heat-inactivated interleukin-1 injected, or sham injected controls. however, sham injected and heat-inactivated interleukin-1 injected sn ... | 1995 | 7821403 |
| biomphalaria glabrata: extensive genetic variation in brazilian isolates revealed by random amplified polymorphic dna analysis. | to examine the extent of genetic variation in biomphalaria glabrata, the intermediate host of schistosoma mansoni, specimens from seven brazilian isolates were studied. regions of genomic dna were amplified using short, arbitrarily selected oligonucleotide primers under low-stringency conditions (random amplified polymorphic dnas--rapds) and analyzed by polyacrylamide gel electrophoresis followed by silver staining. the rapd profiles of snails of the same isolate were relatively homogeneous, wit ... | 1994 | 7914497 |
| interspecific stimulation of parthenogenesis in schistosoma intercalatum and s. mansoni. | experimental studies of mating behaviour of schistosoma intercalatum and schistosoma mansoni in mixed infections in mice showed that in simultaneous infections, without the possibility of choice of mate, heterologous pairing occurs readily. the paired females reach sexual maturity, are inseminated and lay parthenogenetic eggs. miracidia originating from the s. mansoni male x s. intercalatum female are non infective to either biomphalaria glabrata or bulinus forskalii, whereas those from the reve ... | 1994 | 7930460 |
| [preliminary trials of guaiacum officinale l. as a molluscicide]. | aqueous suspensions of fruit's pericarp, leaves, root's bark and seeds of guaiacum officinale were tested at different concentrations as molluscicide, cercaricide and piscicide. in the laboratory the suspension of fruit's pericarp produced 100% mortality for egg masses of b. glabrata at 100 ppm, for adult snails of biomphalaria glabrata, b. straminea and b. tenagophila at 20 ppm, for lebistes reticulatus (fishes) at 5 ppm and schistosoma mansoni's cercariae at 1 ppm. the ethanolic extract of fru ... | 1993 | 7997754 |
| [relationship between the pathogenicity of schistosoma mansoni in mice and the susceptibility of the mollusk vector. ii. number of eggs in feces and number and size of granuloma in visceras]. | the influence of the susceptibility of the vector snails of s. mansoni on the development of the pathogenicity of the worm to the host was studied. off-spring of snails biomphalaria glabrata and biomphalaria tenagophila were used, selected with regard to the susceptibility to s. mansoni of the strains bh and sj trait, respectively. parenteral, f1, f2, f3 and f4 generation cercariae were used for the infection of swiss mice, which were killed eight weeks after infection. the number of eggs in the ... | 1993 | 7997811 |
| characterization of immunoreactive tnf alpha molecules in the gastropod biomphalaria glabrata. | in recent years, several studies have demonstrated the existence of cytokine-like molecules in invertebrates, therefore suggesting that cytokines may have been conserved throughout evolution. in this study, we investigated the presence of immunoreactive tnf alpha (ir tnf alpha) in the gastropod mollusc biomphalaria glabrata, the specific intermediate host for the trematode schistosoma mansoni. immunocytochemical study indicated the presence of ir tnf alpha in mollusc hemocytes corresponding to a ... | 1994 | 8001700 |
| interleukin 1 activity in haemolymph from strains of the snail biomphalaria glabrata varying in susceptibility to the human blood fluke, schistosoma mansoni: presence, differential expression, and biological function. | cytokines control many of the steps in the complex pathways of immune and inflammatory responses in mammals. recent reports also indicate that some invertebrates may produce cytokines such as interleukin 1 (il-1). certain strains of the snail, biomphalaria glabrata (intermediate host for the human blood fluke, schistosoma mansoni), possess a soluble plasma factor that stimulates the haemocyte-mediated killing of larval schistosomes, making them resistant to infection. in this study, we have soug ... | 1994 | 8003629 |
| parthenogenesis in the genus schistosoma: electrophoretic evidence for this reproduction system in s. japonicum and s. mansoni. | mixed infections with schistosoma japonicum and s. mansoni were carried out in mice. s. japonicum females paired with s. mansoni males developed normally and produced numerous viable eggs; very little sperm was found in the female genital tract. the eggs yielded many miracidia infective to oncomelania hupensis, the host of s. japonicum. cercariae arising from miracidia developed into male worms with an electrophoretic pattern of malate dehydrogenase (mdh) corresponding only to the maternal speci ... | 1994 | 8036230 |
| schistosoma mansoni: modulation of hemocyte surface polypeptides detected in individual snails, biomphalaria glabrata, following larval exposure. | as an approach to better understand the molecular mechanisms underlying the differential cellular response to larval schistosoma mansoni observed in biomphalaria glabrata, we have analyzed hemocyte membrane-associated polypeptides from inbred susceptible and resistant strains of b. glabrata. a combination of techniques involving biotin-labeling of cell surface-exposed polypeptides and a highly sensitive chemiluminescent detection technique has allowed the identification of major polypeptides exp ... | 1994 | 8050520 |
| schistosoma mansoni: relationship between low fecundity and reduced susceptibility to parasite infection in the snail biomphalaria glabrata. | biomphalaria glabrata snails which were not susceptible as juveniles to infection by schistosoma mansoni were selectively bred (by self-fertilization) from the highly susceptible nmri laboratory snail stock. the susceptibility rate among juvenile snails derived from interbreeding nmri parents was initially 85-95%, but after several generations of selection, less than 5% of exposed snails became infected by the parasite. selection for low susceptibility also resulted in a large proportion of snai ... | 1994 | 8050522 |
| the introduction of melanoides tuberculata (mollusca: thiaridae) to the island of saint lucia (west indies) and its role in the decline of biomphalaria glabrata, the snail intermediate host of schistosoma mansoni. | a malacological survey was carried out in may 1992 in the whole hydrographic system of saint lucia 11 years after the end of a biological control programme to eliminate biomphalaria glabrata, the snail intermediate host of schistosoma mansoni. a competitor snail, melanoides tuberculata, was introduced to saint lucia in 1978 and field experiments in several habitats were conducted by prentice between 1978 and 1986. at the present time m. tuberculata is the most common freshwater snail in saint lu ... | 1993 | 8103624 |
| surface membrane polypeptides associated with hemocytes from schistosoma mansoni-susceptible and -resistant strains of biomphalaria glabrata (gastropoda). | previous studies have shown that hemocytes from inbred susceptible and resistant strains of the snail, biomphalaria glabrata, differentially react to primary sporocysts of the blood fluke, schistosoma mansoni. it has been hypothesized that this differential reactivity may be due to differences in the expression of hemocyte surface determinants serving as parasite recognition and/or hemocyte activating factors. in order to begin addressing this hypothesis the hemodynamics and surface polypeptides ... | 1994 | 8106743 |
| [urban focus of schistosomiasis in a metropolitan area in a southeastern region of brazil]. | urban focus of schistosomiasis in an urban area of south-eastern, brazil. an active, urban focus of schistosomiasis in belo horizonte, mg, brazil is described. it is located in the "julien rien" park, a leisure area of 48,500 m2 created by the local administration in 1980 on the south side of city. snail captures were made over 10 years (1983-1992) resulting in the collection of 3,361 biomphalaria glabrata, ranging from 6.4 to 12.8 mm in diameter (mean = 9.3); 23 (0.7%) of these were found to be ... | 1993 | 8115836 |
| high performance thin-layer chromatographic analysis of sugars in biomphalaria glabrata (gastropoda) infected with echinostoma caproni (trematoda). | high performance thin-layer chromatographic analysis was done on the hemolymph and digestive gland-gonad complex (dgg) of biomphalaria glabrata snails experimentally infected with the intramolluscan stages of echinostoma caproni. the major sugars detected in both the dgg and hemolymph of infected and uninfected snails were glucose and trehalose. quantitative analysis by scanning densitometry showed a significant reduction in glucose in both the hemolymph and dgg of infected snails at 4, 6, and 8 ... | 1994 | 8158483 |
| transfer of resistance to schistosoma mansoni in biomphalaria glabrata by allografts of amoebocyte-producing organ. | allografts of amoebocyte-producing organ (apo) were implanted heterotopically into the schistosome-susceptible nih albino stock of biomphalaria glabrata from either 13-16-r1 (a schistosome-resistant stock) or nih albino donors. at 3, 7-8, 14-15, 21, 28-33, or 47-71 days postimplantation (pi), allograft recipients were exposed to 50 miracidia each of schistosoma mansoni and subsequently monitored for development of sporocysts and cercariae. relative to untampered snails and recipients of nih albi ... | 1994 | 8195947 |
| schistosoma mansoni: analysis of an unusual infection phenotype in the intermediate host snail biomphalaria glabrata. | snails from a b. glabrata stock, selected for nonsusceptibility to the nmri strain of s. mansoni, exhibited unusual schistosome infections, with multiple sporocysts prominent in the head-foot (foot-sporocysts). when f1 progeny from numerous crosses between well-defined susceptible (s) and resistant (r) parental snails were exposed, 60% of the infected snails also exhibited this unusual phenotype. f1 progeny from s x s snail crosses developed normal infections. foot-sporocysts usually developed m ... | 1993 | 8224090 |
| biochemical and morphological pathology of the foot of the schistosome vector biomphalaria glabrata infected with schistosoma mansoni. | infection by schistosoma mansoni resulted in morphological and biochemical changes to the foot of its intermediate host, biomphalaria glabrata. migration through, and emergence of cercariae from, the foot was observed and evidenced by lesions on the ciliated foot surface. this was accompanied by a significant decrease in the velocity of movement by infected individuals. in vivo 31p nmr spectral analyses demonstrated that the foot of infected snails had a lower phosphoarginine (pa)/adenosine 5' t ... | 1993 | 8233591 |
| morphological characterization of the hemocytes of the pulmonate snail biomphalaria tenagophila. | the blood cells of the pulmonate snail biomphalaria tenagophila, an important transmitter of the trematode schistosoma mansoni in brazil, were examined by light and transmission electron microscopy (tem). two hemocyte types were identified: hyalinocytes and granulocytes. hyalinocytes are small young (immature), poorly spreading cells, which have a high nucleocytoplasmic ratio and are especially rich in free ribosomes. they do not appear to contain lysosome-like bodies and represent less than 10% ... | 1993 | 8246758 |
| transmission of schistosoma mansoni under experimental conditions using the bovine--biomphalaria glabrata-bovine model. | three calves experimentally infected with schistosoma mansoni, and passing viable eggs in feces, as well as 5 normal calves (coming from a non-endemic area for schistosomiasis) kept as controls, were maintained in an enclosure (850 m2 in area). in this enclosure, a tank with water received 500 laboratory reared biomphalaria glabrata. all the control calves were infected for a period ranging from 79 to 202 days after the beginning of the experiment, and afterwards presented viable s. mansoni eggs ... | 1993 | 8278740 |
| compatibility of one brazilian and two venezuelan strains of schistosoma mansoni with various strains of biomphalaria glabrata. | for evaluation of the degree of genetic heterogeneity in parasite and snail strains, the compatibility between biomphalaria glabrata and schistosoma mansoni from different geographical areas was studied. venezuelan snails from bárbula, manuare (areas of schistosome transmission) and tinaquillo (non-transmission area) and brazilian bh snails were exposed to infection with miracidia of both the venezuelan yt and sm strains and the brazilian bh strain of s. mansoni. snail-parasite compatibility was ... | 1993 | 8415568 |
| effects of schistosoma mansoni infection on phagocytosis and killing of proteus vulgaris in biomphalaria glabrata hemocytes. | with the use of a fluorescence microassay, in vitro phagocytosis and killing of proteus vulgaris were measured in hemocytes of nih albino biomphalaria glabrata infected with schistosoma mansoni for 1, 2, 3, or 4 wk. although hemocytes of infected snails displayed decreased phagocytosis, relative to hemocytes of uninfected snails, at 4 wk postinfection (pi), they exhibited enhanced microbicidal activity at 3 wk pi. no microbicidal activity was detected in the plasma of either infected or uninfect ... | 1993 | 8459340 |
| polypeptides synthesized in vitro by biomphalaria glabrata hemocytes bind to schistosoma mansoni primary sporocysts. | in vitro labeled polypeptides secreted by schistosome-susceptible and -resistant biomphalaria glabrata were tested for their ability to bind the surface tegument of schistosoma mansoni primary (= mother) sporocysts. out of a complex pattern of sds-page-separated hemocyte polypeptides, only two (19 and 46 kda) bound to sporocysts. the 19-kda polypeptide consistently bound to both live and fixed sporocysts, although fixed larvae usually bound more than living sporocysts. the 46-kda component bound ... | 1993 | 8463708 |
| comparison of hemocyte components from schistosoma mansoni (trematoda)-susceptible and resistant biomphalaria glabrata (gastropoda) that cross-react with larval schistosome surface proteins. | 1. cross-reactive antigens between larval schistosoma mansoni and hemocytes from schistosome-resistant and susceptible strains of biomphalaria glabrata were identified and compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), immunoblotting and surface radioiodination. 2. four sporocyst (larval s. mansoni) surface antigens (27, 39, 40 and 70 kda) reacted with antibodies to hemocytes from resistant snails whereas only one surface antigen (70 kda) was recognized by a ... | 1993 | 8472536 |
| production of heterogeneous carbohydrate-binding proteins by the host snail biomphalaria glabrata following exposure to echinostoma paraensei and schistosoma mansoni. | hemolymph lectins may play an important role in the internal defense responses of gastropods to parasites. two groups of known carbohydrate-binding polypeptides, of 150-220 kda (designated as group 1 molecules, or g1m) and of 75-130 kda (group 2 molecules, or g2m), were harvested from pooled plasma samples of biomphalaria glabrata using affinity chromatography and examined using 2-dimensional electrophoresis. plasma samples were derived from control snails or snails exposed 8 days earlier to the ... | 1993 | 8501600 |
| development of schistosoma mansoni in biomphalaria tenagophila, biomphalaria straminea and biomphalaria glabrata. | a comparative study of the development of schistosoma mansoni during the intra-molluscan phase was made by means of histological sections of biomphalaria tenagophila, b. straminea and b. glabrata from brazil. two hundred snails of each species were individually exposed to 50 miracidia of the s. mansoni, al line. no larvae were observed in the snails fixed 72 h after exposure. in specimens shedding cercariae, 31 days after exposure tissue reactions encapsulating the larvae were seen in b. tenagop ... | 1995 | 8525264 |
| dna polymorphism of schistosomes and their snail hosts. | analysis of the genomes of schistosomes and one of their intermediate hosts, biomphalaria glabrata, using random amplified polymorphic dna (rapd) demonstrated that intraspecific genetic polymorphism in the parasite is limited but in the snail is highly pronounced. this suggests an important role for the snail in the determination of the epidemiology of the disease. in addition to their intraspecific stability, schistosome derived rapds exhibit a high level of interspecific polymorphism and are t ... | 1995 | 8531659 |
| a method for immunoisolation of sporocysts of schistosoma mansoni in nonsusceptible snails. | a technique is described for immunoisolation of sporocysts of schistosoma mansoni in nonsusceptible biomphalaria glabrata by microencapsulation in agarose. based on histological evidence, all 11 microencapsulated sporocysts implanted into 3 schistosome-resistant 13-16-r1 snails were alive at 72 hr postimplantation, although in a developmentally retarded condition. however, among 146 sporocysts derived from miracidia that had penetrated 5 snails, 96% were dead by 72 hr. these results suggest that ... | 1995 | 8544049 |
| schistosoma mansoni: changes in the albumen gland of biomphalaria glabrata snails selected for nonsusceptibility to the parasite. | the lac-line strain of the snail biomphalaria glabrata has very low susceptibility to the parasite schistosoma mansoni and a very low reproductive potential. upon examination of the reproductive tract of these snails, light and electron microscopy revealed obvious abnormalities in the albumen gland. secretory cells that are normally cuboidal in susceptible nmri (f0) snails were squamous in lac-line snails. these lac-line cells contained small secretory granules and negligible rough endoplasmic r ... | 1995 | 8544062 |
| longitudinal study of circadian rhythms in the cercarial emergence of schistosoma mansoni from biomphalaria glabrata. | | 1995 | 8551950 |
| cercarial emergence of schistosoma mansoni from biomphalaria glabrata and biomphalaria straminea. | | 1995 | 8569474 |
| the plasma proteins of biomphalaria glabrata in the presence and absence of schistosoma mansoni. | snail plasma serves as both a sink for metabolites and a source of nutrients for parasites developing within their intermediate hosts. it also contains molecules involved in immunological events like non-self recognition, phagocytosis and encapsulation. in this study we present improved protocols for the separation and partial characterization of plasma proteins of schistosome-susceptible and resistant strains of biomphalaria glabrata. within each strain, the plasma of snails 12, 24, 48 and 72 h ... | 1995 | 8595817 |
| influence of temperature on development of schistosoma mansoni female cercariae in biomphalaria glabrata. | in these experiments the ratio of male to female s. mansoni larvae in b. glabrata from belo horizonte and ribeirão das neves minas gerais, brazil, either reared in laboratory or collected in the field, varied from 1:1 to 1:1.3 or 1.4:1. cercariae of le strain of schistosoma mansoni, shed by 39 snails maintained at 25 +/- 0.5 degrees c were used to infect mice on a weekly basis. subsequent perfusion resulted in 76.6% male and 23.4% female worms. the cercariae produced by 32 infected snails mainta ... | 1995 | 8599060 |
| use of rapd-pcr to differentiate genetically defined lines of an intermediate host of schistosoma mansoni, biomphalaria glabrata. | the genetic differentiation among several laboratory-maintained pedigree snail lines of biomphalaria glabrata (with different susceptibility phenotypes to schistosoma mansoni infection) was assessed with the random amplified polymorphic dna method. out of the 20 primers tested, 2 (opa-01 and opa-06) gave reproducible markers with either individual or bulked dna samples from resistant (bs-90, 10-r2, lac-line) and susceptible (m-line) snails. arbitrary primer, opa-01, amplification of bs-90 dna id ... | 1996 | 8604090 |
| killing of schistosoma mansoni sporocysts by biomphalaria glabrata hemolymph in vitro: alteration of hemocyte behavior after poly-l-lysine treatment of plastic, and the kinetics of killing by different host strains. | behavior of hemocytes of the gastropod mollusc biomphalaria glabrata was markedly changed on plastic by treatment of the substrate with 0.1 mg/ml poly-l-lysine compared to behavior on untreated plastic. on lysine, the cells showed minimal spreading, moved significantly faster, and formed aggregates. cell-mediated cytotoxicity (cmc) assays were set up on the modified and untreated substrates to compare the killing capacities of b. glabrata hemocytes against schistosoma mansoni sporocysts. hemolym ... | 1996 | 8604109 |
| inhibition of cysteine proteinase from schistosoma mansoni larvae by alpha-macroglobulin from the plasma of biomphalaria glabrata. | the hemolymph of biomphalaria glabrata, a molluscan host of schistosoma mansoni, contains an alpha-macroglobulin proteinase inhibitor (alpham). in this study we have demonstrated that this host molecule inhibits a cysteine proteinase produced by larval s. mansoni. inhibition by alpham involves conformational changes through proteolytic cleavage by the proteinase, thus the enzyme must be active for interactions to occur. a specific cysteine proteinase inhibitor (e64) was used to block the interac ... | 1996 | 8604113 |
| male reproductive success of schistosoma mansoni-infected biomphalaria glabrata snails. | infection of biomphalaria glabrata by schistosoma mansoni results in a dramatic reduction in the snail's ability to produce eggs. we studied the ability of such parasitically castrated snails to fertilize the eggs of uninfected snails. pigmented b. glabrata snails (13141 stock) were infected with s. mansoni miracidia and reared individually until they ceased laying eggs. these infected snails were then given the opportunity to mate with uninfected albino (nmri) snails. each of the infected snail ... | 1996 | 8636847 |
| analysis of lectin- and snail plasma-binding glycopeptides associated with the tegumental surface of the primary sporocysts of schistosoma mansoni. | carbohydrates associated with the tegumental surface of schistosoma mansoni primary sporocyst may serve as potential receptors for mediating recognition by the internal defence system of the molluscan host, biomphalaria glabrata. therefore, a combination of sds-page and lectin probe analyses were carried out on biotin-labelled tegumental glycopeptides as a first step to defining the carbohydrates expressed at the sporocyst surface. the majority of surface polypeptides, ranging in relative molecu ... | 1996 | 8677136 |
| biomphalaria glabrata: a new threat for schistosomiasis transmission in egypt. | this is the first report on the infestation of irrigation and drainage systems at giza, qalyoubiya and kafr el shiekh governorates, with biomphalaria glabrata (the snail host of schistosoma mansoni in the new world). identification of this snail species was based on morphometry of the shell, shape of the radular lateral teeth and presence of the characteristic renal ridge. b. glabrata snails collected from natural water courses in egypt proved to be susceptible to a local strain of s. mansoni. t ... | 1996 | 8721240 |
| [relationship between the pathogenicity of schistosoma mansoni in mice and the susceptibility of the vector mollusk. iii. mortality, body and viscera weight]. | the relationship between the development of hepatomegaly, splenomegaly, body weight and mortality rate and the degree of susceptibility of biomphalaria glabrata and b. tenagophila at which infective cercariae developed was studied. the study utilized swiss mice, spf, as definitive hosts and populations of snails genetically selected for character susceptibility as intermediate hosts. low body weight and smaller viscera were observed in infected mice with cercariae originating from snails that sh ... | 1995 | 8729275 |
| phagocytosis of latex beads by biomphalaria glabrata hemocytes is modulated in a strain-specific manner by adsorbed plasma components. | circulating phagocytes of the mollusc biomphalaria glabrata help determine the fate of invading schistosoma mansoni larvae. in mediating cytotoxicity against this trematode parasite, phagocytic hemocytes may interact with unidentified plasma components. in this study, positively and negatively charged latex beads were coated with plasma for use in in vitro phagocytosis assays. hemocytes from s. mansoni-susceptible and -resistant strains of b. glabrata were tested for their ability to internalize ... | 1996 | 8738934 |
| biogenic monoamines in the freshwater snail, biomphalaria glabrata: influence of infection by the human blood fluke, schistosoma mansoni. | the biogenic monoamines, serotonin (5-ht), dopamine (da) and l-dopa were measured using high performance liquid chromatography with electrochemical detection (hplc-ed) in the extracts of the central nervous system (cns) and plasma of uninfected freshwater snails, biomphalaria glabrata, and in snails at 7, 14, 21 and 28 days postexposure (pe) to the miracidia of the human blood fluke, schistosoma mansoni. relative to age-matched uninfected snails, a general depression of biogenic amine levels was ... | 1996 | 8759145 |
| circadian pattern of cercarial emergence in schistosoma mansoni (platyhelminthes:digenea) from isolated biomphalaria glabrata. | the present work aimed to compare the acrophases (peak hours) of emergence of schistosoma mansoni cercariae among isolated individuals of the snail biomphalaria glabrata. laboratory stocks of melanic b. glabrata from the same biotope as the s. mansoni strain (belo horizonte, minas gerais) were used. twenty-two snails individually exposed to five miracidia were tested. chronobiological trials were performed outdoors after an acclimation period of at least a week. three groups of snails were teste ... | 1996 | 8877118 |
| identification of the first major allergen of a squid (todarodes pacificus). | in japan, squid is an important seafood, and some patients with food allergies are sensitive to squid. there has been no report, however, describing the major allergens of squid. | 1996 | 8939158 |
| schistosoma mansoni: use of a subtractive cloning strategy to search for rflps in parasite-resistant biomphalaria glabrata. | a subtractive cloning strategy has been applied for the identification of two cdna clones whose corresponding transcripts were elevated in schistosoma mansoni-resistant (bs-90) compared to susceptible (m-line) snails. clone pbs11 encoded a 1.9-kb transcript that was more elevated compared to a 500-bp transcript encoded by clone pbs12. consequently, more attention was focused on the molecular characterization of clone pbs11. results showed that the transcript encoded by this clone was expressed i ... | 1996 | 8948331 |
| schistosoma mansoni: distribution patterns of miracidia among biomphalaria glabrata snail as related to host susceptibility and sporocyst regulatory processes. | parasite prevalences, miracidia developmental capacity, mother sporocyst mean intensities, sporocyst distribution patterns, and cercarial production levels were determined after individual exposure of biomphalaria glabrata snails to increased doses of schistosoma mansoni miracidia for two geographical strains (brazilian, bre, and guadeloupean, gua) of host and parasite. for a high level (100%) of host-parasite susceptibility and in the absence of mother sporocyst regulatory processes for the bre ... | 1997 | 9024196 |
| urban schistosomiasis: morbidity, sociodemographic characteristics and water contact patterns predictive of infection. | schistosomiasis (schistosoma mansoni) is classically described as a rural disease that occurs in areas with poor sanitary conditions. this cross-sectional study was undertaken in a suburban area of a large industrialized city in brazil (belo horizonte), aiming at examining epidemiological characteristics of schistosomiasis in an urban setting. | 1996 | 9027538 |
| schistosoma mansoni: the sex ratios of worms in animals infected with cercariae from three species of biomphalaria. | the ratios of male to female worms of schistosoma mansoni were determined in mice infected with cercariae from le, sj and al strains shed by mollusc hosts of the parasite in brazil. the sex ratios of worms in the animals were similar with cercariae from biomphalaria glabrata and b. tenagophila varying from 1.1:1 to 1.6:1 with le and al strains and 1:1.1 with sj. in the animals infected with cercariae from b. straminea the ratio of male to female worms was similar to those obtained using cercaria ... | 1996 | 9071034 |
| schistosoma mansoni: the ultrastructure of larval morphogenesis in biomphalaria glabrata and of associated host-parasite interactions. | an electron microscopic study has been carried out to describe the transformation of the miracidium of s. mansoni into the mother sporocysts in the susceptible b. glabrata and the associated host-parasite interactions. the miracidium enters the snail host without morphological alterations. within 3 hr after entering, all the ciliary epidermal plates of the miracidium are discarded. a new tegument is quickly formed by 5 hr postinfection by the expansion of epidermal ridges. the rapid formation of ... | 1996 | 9086392 |
| change in schistosome sex ratio under the influence of a biotic environmental-related factor. | schistosoma mansoni is a dioecious trematode responsible for intestinal schistosomiasis in man. the sex ratio was determined for s. mansoni adults derived from cercariae obtained from infected biomphalaria glabrata maintained in the presence of the nonvector molluse. marisa cornuarietis. the presence of m. cornuarietis is responsible for enhanced growth of b. glabrata and for a change in the sex ratio of the schistosome, which becomes more male-biased as compared to control snails maintained in ... | 1997 | 9105300 |
| altered nutrition and assimilation of the snail host (biomphalaria glabrata) as a consequence of the parasitic spatial constraint (schistosoma mansoni). | | 1996 | 9133164 |
| schistosoma mansoni: cercarial shedding patterns from a mixed infection of biomphalaria glabrata with two (early and late) chronobiological variants. | the cercarial emergence rhythms of schistosoma mansoni were analyzed for mixed infection of the snail biomphalaria glabrata with two chronobiological strains, one with an early shedding pattern and the other with a late shedding pattern. under these conditions, each parasite strain kept its own circadian cercarial emergence pattern. when the chronobiological variants were of the same species, no interference between the trematode larvae occurred during the cercarial emergence process. these resu ... | 1997 | 9134557 |
| detection of schistosoma mansoni in biomphalaria using nested pcr. | a nested polymerase chain reaction (pcr) protocol was developed for detecting the presence of schistosoma mansoni sporocysts in intermediate host snails of the genus biomphalaria. to accomplish this, rdna genes encoding the 18s rrna of s. mansoni and biomphalaria alexandrina from egypt were sequenced, as were 18s-encoding genes of the 13-16-r1 and salvador strains of biomphalaria glabrata. based on a comparison of host and parasite sequences, a nested set of pcr primers was designed to allow spe ... | 1997 | 9194817 |
| pcr amplification of the mitochondrial dna minisatellite region to detect schistosoma mansoni infection in biomphalaria glabrata snails. | schistosoma infection in biomphalaria glabrata can be detected by either exposing snails to light to induce cercarial shedding or by squeezing them between glass slides to detect parasites in the digestive gland and other regions. the methods available are inefficient for identification of prepatent infections and do not allow the diagnosis of infection in snails that die before arriving in the laboratory. furthermore, infection is undetectable after migration of sporocysts from the head-foot re ... | 1997 | 9194818 |
| [behavior of hemolymph amebocytes from planorbidae in the presence of schistosoma mansoni larvae parasitism, after inoculation of indian ink or fracture of the shell]. | the behavior of the hemolymph amebocytes of biomphalaria glabrata and biomphalaria tenagophila was studied by means of the infection by the schistosoma mansoni, using inoculation with indian ink and fracture of the shell. a differential count of the amebocytes in the hemolymph was made with special attention given to the types of cell found in each sample. histopathological evaluation of the molluscs exposed to the schistosoma mansoni miracidia and analyses of the amebocytes were made. correlati ... | 1996 | 9201894 |
| a family of fibrinogen-related proteins that precipitates parasite-derived molecules is produced by an invertebrate after infection. | after infection with the digenetic trematode echinostoma paraensei, hemolymph of the snail biomphalaria glabrata contains lectins comprised of 65-kda subunits that precipitate polypeptides secreted by e. paraensei intramolluscan larvae. comparable activity is lacking in hemolymph of uninfected snails. three different cdnas with sequence similarities to peptides derived from the 65-kda lectins were obtained and unexpectedly found to encode fibrinogen-related proteins (freps). these freps also con ... | 1997 | 9238039 |
| [the resistance of biomphalaria glabrata to schistosoma mansoni infection: variations in the prepatent period and in compatibility]. | biomphalaria glabrata from belo horizonte, minas gerais, brazil, reared in laboratory, has a level of infection of 90% when exposed to 20 miracidia of the autochibonous le strain. the prepatent period was of 5 to 7 weeks whereas 5 to 10% of exposed snails do not shed cercariae. the eggs of negative snails were collected and the progeny was again submitted to individual infection with 20 miracidia. the mean of infection from f14 to f20 was of 43.6%. histological sections from f12, f14 and f15 sna ... | 1997 | 9265222 |