| hemozoin formation in echinostoma trivolvis rediae. | rediae of the trematode echinostoma trivolvis, from naturally infected helisoma trivolvis snails, form a black pigment while inside the snail host. here we examine the black pigment to show that the insolubility characteristics in detergent and weak base solution are identical to plasmodium falciparum hemozoin. laser desorption mass spectrometry of the purified pigment demonstrates the presence of heme. examination of purified pigment under polarized light microscopy illuminates ordered birefrin ... | 2005 | 16019007 |
| influence of saccharose on the development of cercariae from schistosoma mansoni strains bh and sj. | the development of cercariae from schistosoma mansoni strains bh and sj in biomphalaria glabrata and biomphalaria tenagophila treated with saccharose was studied. the molluscs were maintained in dechlorinated tap water containing 0.01% saccharose. after one week of treatment with saccharose, b. glabrata and b. tenagophila were exposed to ten s. mansoni miracidia, from bh and sj strains respectively. control snails of both species were maintained in dechlorinated tap water without saccharose and ... | 2005 | 16025902 |
| manganese superoxide dismutase from biomphalaria glabrata. | the investigation of the response of biomphalaria glabrata snails to echinostoma paraensei (digenea) at 2 days post-exposure by suppression subtractive hybridization yielded a partial sequence of the anti-oxidant enzyme manganese superoxide dismutase (mnsod). full-length mnsod (669nt) from m line and bs-90 strains of b. glabrata differed by one synonymous nucleotide replacement. b. glabrata has 1-4 mnsod loci (southern hybridization). both snail strains expressed mnsod at equal baseline levels ( ... | 2005 | 16081093 |
| [schistosomiasis mansoni in two mesoregions of the state of alagoas]. | in brazil, high levels of schistosomiasis mansoni are linked to the presence of the species biomphalaria glabrata, considered to be the main host of schistosoma mansoni in endemic areas. this work conducted a survey of 40 endemic municipalities in the state of alagoas, aiming at identifying this species and its important role in the maintenance of schistosomiasis. among the municipalities surveyed, 28 lie in the mesoregion of the leste alagoano and 12, in the mesoregion of the agreste alagoano. ... | 2005 | 16082475 |
| characterization of adenosine deaminase (ada) in hemolymph of biomphalaria glabrata. | adenosine is an important signaling molecule for many cellular events. adenosine deaminase (ada) is a key enzyme for the control of extra- and intra-cellular levels of adenosine. activity of ada was detected in hemolymph of b. glabrata and its optimum assay conditions were determined experimentally. the ph variation from 6.2 to 7.8 caused no significant change in ada activity. using adenosine as a substrate, the apparent km at ph 6.8 was 734 micromols.l(-1). highest activity was found at 37 degr ... | 2005 | 16097741 |
| multi-species interactions among a commensal (chaetogaster limnaei limnaei), a parasite (schistosoma mansoni), and an aquatic snail host (biomphalaria glabrata). | this study assessed the effects of a commensal, chaetogaster limnaei limnaei, and a parasitic trematode, schistosoma mansoni, on infection patterns and life-history responses in the aquatic snail biomphalaria glabrata. prevalence of infection was significantly higher in snails that were devoid of c. limnaei limnaei relative to those that were colonized by the commensal, indicating that the oligochaete may protect the host from trematode infection. this finding appeared to be the direct result of ... | 2005 | 16108575 |
| isolation and characterization of the full-length cdna encoding a member of a novel cytochrome p450 family (cyp320a1) from the tropical freshwater snail, biomphalaria glabrata, intermediate host for schistosoma mansoni. | cytochrome p450s (cyp450s) are a family of structurally related proteins, with diverse functions, including steroid synthesis and breakdown of toxins. this paper reports the full-length sequence of a novel cyp450 gene, the first to be isolated from the tropical freshwater snail biomphalaria glabrata, an important intermediate host of schistosoma mansoni. the nucleotide sequence is 2291 bp with a predicted amino acid sequence of 584aa. the sequence demonstrates conserved cyp450 structural motifs, ... | 2005 | 16113864 |
| are biomphalaria snails resistant to schistosoma mansoni? | among biomphalaria glabrata/schistosoma mansoni snail-trematode combinations, it appears that some parasites succeed whilst others fail to infect snails. snails that become infected are termed susceptible hosts. those which are not infected are traditionally determined as 'resistant'. here the concept of b. glabrata resistance to s. mansoni is re-examined in the light of additional observations. it is suggested that, in b. glabrata/s. mansoni, compatibility is tested independently for each indiv ... | 2005 | 16153311 |
| biological invasions: the case of planorbid snails. | a large number of planorbid snails are now commonly transported by man mainly through the aquatic plant trade. however, only a restricted number of species establish viable populations in a new habitat and a more restricted number spread. only five planorbid species can be ranked in this last category and can be considered as pests because of their role in the transmission of parasites to humans or domestic animals: biomphalaria glabrata, b. straminea, b. tenagophila, b. pfeifferi and indoplanor ... | 2005 | 16153319 |
| [genetic selection of biomphalaria glabrata and biomphalaria tenagophila seeking the alteration of the susceptibility and resistance to schistosoma mansoni]. | generations of biomphalaria glabrata and biomphalaria tenagophila selected genetically for resistance and susceptibility to schistosoma mansoni of strains bh and sj were used in a study of the trematode adaptation to the intermediate host. descendants of the planorbids were obtained by self-fertilization of the mollusks that became susceptible or resistant after exposure to the miracidia of schistosoma mansoni. for biomphalaria glabrata they were obtained from the following generations: parental ... | 2005 | 16172752 |
| [geographic distribution of schistosoma mansoni transmitter snail species in state of são paulo]. | a thorough knowledge of the geographic distribution of schistosoma mansoni vector snails is indispensable for the control of schistosoma mansoni schistosomiasis and its epidemiologic surveillance. from the water masses of the state of são paulo (brazil) 8,771 lots of snails--total of 108,244 individuals of the genus biomphalaria--were captured between 1982 and 2002. these specimens are now part of the malacological collection of (superintendência de controle de endemias--são paulo). according to ... | 2005 | 16172761 |
| application of synchrotron-radiation-based computer microtomography (srict) to selected biominerals: embryonic snails, statoliths of medusae, and human teeth. | synchrotron-radiation-based computer microtomography (srmicroct) was applied to three biomineralised objects first, embryonic snails of the freshwater snail biomphalaria glabrata, second, rhopalia (complex sense organs) of the medusa aurelia aurita, and third, human teeth. the high absorption contrast between the soft tissue and mineralised tissues, i.e. the shell in the first case (consisting of calcium carbonate) and the statoliths in the second case (consisting of calcium sulphate hemihydrate ... | 2005 | 16187072 |
| schistosoma mansoni excretory-secretory products stimulate a p38 signalling pathway in biomphalaria glabrata embryonic cells. | following infection with schistosoma mansoni larvae, haemocytes of resistant biomphalaria glabrata snails execute a rapid defence during which they migrate towards and encapsulate the parasites. such immediate and precise responses are thought to depend on signal transduction cascades though the signalling components involved remain largely unknown. it is proposed that mitogen-activated protein kinases may play a role in b. glabrata immune signalling, in particular p38 mitogen-activated protein ... | 2006 | 16194541 |
| crystal structure of a novel tetrameric complex of agonist-bound ligand-binding domain of biomphalaria glabrata retinoid x receptor. | nuclear receptors form an important class of transcription regulators in metazoans. to learn more about the evolution of these proteins, we have initiated structural studies on nuclear receptor ligand-binding domains from various animals. here we present the crystal structure of the ligand-binding domain (lbd) of the retinoid x receptor (rxr) from the mollusc biomphalaria glabrata. the structure reveals a novel tetrameric association in which each monomer is complexed to the human rxr ligand 9-c ... | 2005 | 16274693 |
| antiprotozoal and molluscicidal activities of five brazilian plants. | leishmaniasis, chagas' disease and schistosomiasis (bilharzia) are parasitic diseases with wide distribution on the american continent, affecting millions of people. in the present study, biological assays for antiprotozoal and molluscicidal activities were carried out with ethanolic extracts of plant species from the brazilian part of the upper paraná river. crude extracts were obtained by percolation with absolute ethanol from the leaves of cayaponia podantha cogn., nectandra falcifolia (nees) ... | 2005 | 16302102 |
| age of adult worms of echinostoma caproni does not affect development of miracidia. | the effect of the age of adult echinostoma caproni on egg development was studied. the percentage of fully developed miracidia was determined in eggs derived from adult worms obtained from laboratory mice at 2, 4, 6, and 8 wk postinfection (pi). regardless of the age of worms from which the eggs were obtained, the percentage of fully developed miracidia was always >90%, and 60-80% of the eggs hatched. several previous studies have shown that eggs derived from 2- to 4-wk-old e. caproni yielded mi ... | 2005 | 16419773 |
| in vivo and in vitro knockdown of frep2 gene expression in the snail biomphalaria glabrata using rna interference. | rna interference (rnai) is reported here for the first time for biomphalaria glabrata, the snail intermediate host for the human parasite schistosoma mansoni. the fibrinogen-related protein 2 (frep2) gene, normally expressed at increased levels following exposure to digenetic trematode parasites, such as s. mansoni or echinostoma paraensei, was targeted for knockdown. double-stranded rna (dsrna) corresponding to specific regions of the frep2 gene was introduced into snails by direct injection in ... | 2006 | 16442620 |
| the lethality of euphorbia conspicua to adults of biomphalaria glabrata, cercaria of schistosoma mansoni and larvae of artemia salina. | leaf extracts of euphorbia conspicua (euphorbiaceae), together with the latex and fractions derived therefrom, were evaluated for their molluscicidal and cercaricidal activities and their toxicities to brine shrimps. whilst the leaf extracts were inactive against biomphalaria glabrata, the latex, its triterpenic fraction and irritant fractions i and ii exhibited high activities against adult snails with lc90 values of 4.87, 10.55, 0.64 and 0.10 microg/ml, respectively. the latex and its derived ... | 2007 | 16458000 |
| the snail (biomphalaria glabrata) genome project. | in 2001, ideas for a snail genome project were discussed at the american society of parasitologists meeting (new mexico) and a snail genome consortium was subsequently established (the first consortium meeting was held in 2005). a proposal for sequencing the snail genome was submitted to the national human genome research institute, and biomphalaria glabrata was prioritized as a non-mammalian sequencing target in 2004. the sequencing of the genome of this medically important snail is now underwa ... | 2006 | 16497557 |
| biomphalaria glabrata cytosolic copper/zinc superoxide dismutase (sod1) gene: association of sod1 alleles with resistance/susceptibility to schistosoma mansoni. | variation in susceptibility of the snail biomphalaria glabrata to infection by the parasite schistosoma mansoni is, at least in part, genetically determined. functional studies have demonstrated that hemocyte-mediated killing of the parasite involves hydrogen peroxide, the enzymatic product of superoxide dismutase (sod). the present study identifies alleles of the gene coding for cytosolic copper/zinc sod (sod1). the resistance/susceptibility phenotypes and sod1 genotypes were determined for 354 ... | 2006 | 16564582 |
| physiological changes in biomphalaria glabrata say, 1818 (pulmonata: planorbidae) caused by sub-lethal concentrations of the latex of euphorbia splendens var. hislopii n.e.b (euphorbiaceae). | molluscides have been used as one of the strategies to control schistosomiasis. many plant extracts with molluscidal effects have been tested, but the action of the latex of euphorbia splendens var. hislopii is considered the most promising because it meets the recommendations of the world health organization (who). the objective of this study was to determine the lethal dose and identify the effects of the different doses of latex of e. splendens var. hislopii on the physiology of biomphalaria ... | 2006 | 16612505 |
| behavior of angiostrongylus costaricensis in planorbids. | some terrestrial mollusks are natural hosts of angiostrongylus costaricensis. in the laboratory, this nematode can be maintained in certain planorbids, which are aquatic mollusks and intermediate hosts of schistosoma mansoni. mollusks can be infected with angiostrongylus costaricensis by ingestion of or active penetration by the first-stage larvae. in this work we assessed the ability of biomphalaria glabrata to attract first-stage larvae of a. costaricensis. movement of the nematode larvae towa ... | 2006 | 16710513 |
| geographical variations in infectivity and susceptibility in the host-parasite system schistosoma mansoni/biomphalaria glabrata: no evidence for local adaptation. | we investigated local adaptation in the spatially structured natural biomphalaria glabrata/schistosoma mansoni host-parasite system in the marshy forest focus of guadeloupe using cross-transplantation experiments. we demonstrated strong and highly significant variations in susceptibility/infectivity of host and parasite populations, respectively, but found no evidence of local adaptation neither for s. mansoni nor for b. glabrata. environmental as well as genetic factors are discussed to explain ... | 2006 | 16719959 |
| the effects of temperature change on the infection rate of biomphalaria glabrata with schistosoma mansoni. | the aim of this study was to investigate the influence of temperature on the development of schistosoma mansoni infections in biomphalaria glabrata. the snails were infected at 15, 20, and 30 degrees c, and the cercarial release was analyzed after 30 and 60 days post-infection. our results showed that a decrease in the temperature has a substantial influence on the development of s. mansoni infection in b. glabrata, with significant differences (p < 0.05) between 15 and 30 degrees c. these data ... | 2006 | 16830717 |
| molluscicidal activity of solanum species of the northeast of brazil on biomphalaria glabrata. | seven species of solanum were screened for their molluscicidal properties against biomphalaria glabrata, the intermediated host of schistosoma mansoni, solanum agrarium, s. jabrense, s. melissarum, s. megalonyx, s. paludosum, s. paraibanum and s. stipulaceum. four extracts showed molluscicidal activity with lc(50) from 22 to 56 microg/ml. | 2006 | 16842935 |
| red blood with blue-blood ancestry: intriguing structure of a snail hemoglobin. | the phylogenetic enigma of snail hemoglobin, its isolated occurrence in a single gastropod family, the planorbidae, and the lack of sequence data, stimulated the present study. we present here the complete cdna and predicted amino acid sequence of two hemoglobin polypeptides from the planorbid biomphalaria glabrata (intermediate host snail for the human parasite schistosoma mansoni). both isoforms contain 13 different, cysteine-free globin domains, plus a small n-terminal nonglobin "plug" domain ... | 2006 | 16877545 |
| specific inhibitors of mitogen-activated protein kinase and pi3-k pathways impair immune responses by hemocytes of trematode intermediate host snails. | to characterize molecular mechanisms regulating snail cellular immune responses, the contributions of mitogen-activated protein kinases (mapks) and phosphatidylinositol 3-kinase (pi3-k) were examined in hemocytes of the trematode intermediate host snails biomphalaria glabrata and lymnaea stagnalis. simultaneous measurement of phagocytosis/encapsulation and h2o2 production by hemocytes in the presence or absence of specific signal transduction inhibitors was used to assess the role of extracellul ... | 2007 | 16926049 |
| structural characterization of n-glycans from the freshwater snail biomphalaria glabrata cross-reacting with schistosoma mansoni glycoconjugates. | the human parasitic trematode schistosoma mansoni has a complex life cycle that includes the freshwater snail biomphalaria glabrata as intermediate host. within each stage, the parasite synthesizes a wide array of glycoconjugates, exhibiting, in part, unique carbohydrate structures. in addition, the parasite expresses definitive host-like sugar epitopes, such as lewis x determinants, supporting the concept of carbohydrate-mediated molecular mimicry as an invasion and survival strategy. in the pr ... | 2007 | 16971380 |
| lethal and sub-lethal effects of uvb on juvenile biomphalaria glabrata (mollusca: pulmonata). | although schistosoma mansoni occurs mainly in the tropics, where intense levels of solar radiation are present, the impact of ultraviolet (uv) light on schistosome transmission is not known. the purpose of this study was to investigate potential effects of uvb (290-320nm) on juvenile biomphalaria glabrata, the snail intermediate host of s. mansoni. albino and wild-type snails were exposed to doses of uvb from uv-fluorescent lamps, and the following were measured: survival, photoreactivation (lig ... | 2006 | 16996081 |
| thin layer chromatographic analysis of glucose and maltose in estivated biomphalaria glabrata snails and those infected with schistosoma mansoni. | thin layer chromatography was used to analyze the glucose and maltose concentrations of the digestive gland-gonad complex (dgg) of uninfected-estivated biomphalaria glabrata snails and estivated b. glabrata patently infected with schistosoma mansoni. all snails were estivated in a most chamber at a relative humidity of 98+/-1% and a temperature of 23+/-1 degrees c for 14 days. carbohydrates were extracted from the dgg with 70% aqueous ethanol, and extracts were analyzed on silica gel preadsorben ... | 2006 | 17010650 |
| molecular cloning and characterization of mn-superoxide dismutase from disk abalone (haliotis discus discus). | the mitochondrial enzyme manganese superoxide dismutase (mitmn-sod) is one of the antioxidant enzymes involved in cellular defense against oxidative stress and catalyzes the conversion of o(2)(-) into the stabler h(2)o(2). in this study, a putative gene encoding mn-sod from disk abalone (haliotis discus discus, amn-sod) was cloned, sequenced, expressed in escherichia coli k12(tb1) and the protein was purified using pmal protein purification system. sequencing resulted orf of 681 bp, which corres ... | 2006 | 17020816 |
| surface morphology and characteristics of hemocytes of biomphalaria glabrata (pulmonata: planorbidae) from two geographic sources. | biomphalaria glabrata is a fresh water snail of medical importance since it is the intermediate host of the trematode schistosoma mansoni. the internal defense system of mollusks is mostly represented by circulating elements of the hemolymph (hemocytes). the infectivity of s. mansoni to b. glabrata is determined by genetic factors and evolutionary adaptations. in the present work factors about the parasite/snail relationship were evaluated, especially those related to the morphology and characte ... | 2001 | 17061496 |
| identification of the boudicca and sinbad retrotransposons in the genome of the human blood fluke schistosoma haematobium. | schistosomes have a comparatively large genome, estimated for schistosoma mansoni to be about 270 megabase pairs (haploid genome). recent findings have shown that mobile genetic elements constitute significant proportions of the genomes of s. mansoni and s. japonicum. much less information is available on the genome of the third major human schistosome, s. haematobium. in order to investigate the possible evolutionary origins of the s. mansoni long terminal repeat retrotransposons boudicca and s ... | 2006 | 17072464 |
| primary culture of the region of the amebocyte-producing organ of the snail biomphalaria glabrata, the intermediate host of schistosoma mansoni. | biomphalaria glabrata snails are major hosts for the digenetic trematoda schistosoma mansoni, the causative agent of human schistosomiasis. the success or failure of the infection will be dependent on the mobilization of the molluskan internal defense system, where a major role will be played by circulating hemocytes produced by the apo (amebocyte-producing organ) of the snail. in this report, the primary culture of the apo region of b. glabrata was obtained for the first time, as well as a cont ... | 2006 | 17072476 |
| identification of genes involved in interactions between biomphalaria glabrata and schistosoma mansoni by suppression subtractive hybridization. | biomphalaria glabrata is an intermediate snail host for schistosoma mansoni, a medically important schistosome. in order to identify transcripts involved in snail-schistosome interactions, subtractive cdna libraries were prepared, using suppression subtractive hybridization (ssh) between a parasite-exposed schistosome-resistant and a susceptible strain of b. glabrata, and also between schistosome-exposed and unexposed snails from the resistant snail line. separate libraries were made from both h ... | 2007 | 17081633 |
| biomphalaria glabrata transcriptome: identification of cell-signalling, transcriptional control and immune-related genes from open reading frame expressed sequence tags (orestes). | biomphalaria glabrata is the major intermediate snail host for schistosoma mansoni, one of the important schistosomes infecting man. much remains to be discovered concerning specific molecules mediating the defence events in these intermediate hosts, triggered by invading schistosomes. an expressed sequence tag (est) gene discovery strategy known as orestes has been employed to identify transcripts that might be involved in snail-schistosome interactions in order to examine gene expression patte ... | 2007 | 17208299 |
| dose-dependent schistosome-induced mortality and morbidity risk elevates host reproductive effort. | parasitism changes the host environment and may influence resource allocation between reproductive effort and somatic maintenance. we characterized the impact of dose-dependent schistosome exposure and/or infection establishment on intermediate host survival and reproduction. four matched groups of biomphalaria glabrata snails were individually exposed to increasing doses of schistosoma mansoni parasites, with a fifth control group remaining unexposed. increased mortality was observed amongst bo ... | 2007 | 17209999 |
| discriminant analysis of free fatty acids of some egyptian snails as a step for schistosomiasis control: new trends. | schistosomiasis is still the most common occupational health problem of rural workers in egypt. the use of molluscicides, either chemical or biological, and environmental changing are the most successful methods of snail control. the new trend in schistosoma control programs is to study the ecological factors that attract miracidium schistosoma specific snails, to emphasizing to find out new environmental safe control methods. since schistosoma worms do not make fatty acids de novo, they require ... | 2000 | 17219851 |
| [spatial analysis of biomphalaria glabrata foci and human cases of mansoni schistosomiasis in porto de galinhas, pernambuco state, brazil, in the year 2000]. | this article provides information on the spatial distribution of schistosomiasis, correlating snail foci with human cases using spatial analysis. the locations studied were merepe iii, pantanal, salinas, and socó, comprising 70% of the populated area of porto de galinhas. malacological and parasitological surveys by a cpqam/ fiocruz team at the location where an epidemic occurred in 2000 identified 15 foci of infected b. glabrata. human cases were also diagnosed and recorded according to residen ... | 2007 | 17221090 |
| bioassay guided isolation of a new c18-polyacetylene, (+)-9(z),17-octadecadiene-12,14-diyne-1,11,16-triol, from cassonia barteri. | a novel c18-polyacetylene, (+)-9( z),17-octadecadiene-12,14-diyne-1,11,16-triol, has been isolated from the ethyl acetate extract of cassonia barteri (araliaceae) leaves collected in cameroon. the structure determination was achieved by nmr, mass, ir, and uv spectroscopy. the new polyenyne shows antibacterial activity against bacillus subtilis and pseudomonas fluorescens, antifungal activity against cladosporium cucumerinum, moiluscicidal activity against biomphalaria glabrata at low concentrati ... | 1998 | 17253268 |
| variation in expression of biomphalaria glabrata sod1: a potential controlling factor in susceptibility/resistance to schistosoma mansoni. | the snail biomphalaria glabrata kills the blood fluke schistosoma mansoni by a mechanism involving production of hydrogen peroxide, the enzymatic product of cytosolic cu/zn superoxide dismutase (sod1). this enzyme exhibits higher activity in blood cells (hemocytes) from a predominantly resistant strain of b. glabrata than in hemocytes from a susceptible strain. additionally, b. glabrata sod1 polymorphisms have been associated with susceptibility/resistance to the parasite. to address the hypothe ... | 2007 | 17292470 |
| a bacterial artificial chromosome library for biomphalaria glabrata, intermediate snail host of schistosoma mansoni. | to provide a novel resource for analysis of the genome of biomphalaria glabrata, members of the international biomphalaria glabrata genome initiative (http://biology.unm.edu/biomphalaria-genome.html), working with the arizona genomics institute (agi) and supported by the national human genome research institute (nhgri), produced a high quality bacterial artificial chromosome (bac) library. the bb02 strain b. glabrata, a field isolate (belo horizonte, minas gerais, brasil) that is susceptible to ... | 2006 | 17308766 |
| differential lectin labelling of circulating hemocytes from biomphalaria glabrata and biomphalaria tenagophila resistant or susceptible to schistosoma mansoni infection. | lectins/carbohydrate binding can be involved in the schistosoma mansoni recognition and activation of the biomphalaria hemocytes. therefore, expression of lectin ligands on biomphalaria hemocytes would be associated with snail resistance against s. mansoni infection. to test this hypothesis, circulating hemocytes were isolated from b. glabrata bh (snail strain highy susceptible to s. mansoni), b. tenagophila cabo frio (moderate susceptibility), and b. tenagophila taim (completely resistant strai ... | 2006 | 17308768 |
| a contribution to the pathobiology of biomphalaria glabrata hemocytes. | this study attempts to investigate the relationship between the hemocytes in the two compartments: circulating peripheral lymph and the connective tissues. the hemocytes are compared with the vertebrate macrophages and constitute the principal line of defense against external aggression. the hemocytes were counted in circulating hemolymph and their phagocytic capability was evaluated in schistosoma mansoni-infected biomphalaria glabrata and the results were compared with those obtained from norm ... | 2006 | 17308769 |
| changes induced in biomphalaria glabrata (say, 1818) following trials for artificial stimulation of its internal defense system. | biomphalaria glabrata can react through different pathways to schistosoma mansoni miracidium penetration, according to the degree of resistance/susceptibility presented by different snail strains, which is a genetically determined character, resistance being the dominant feature. however, it has been observed that previous susceptible snail strain may change its reactive behavior along the course of infection, exhibiting later a pattern of cercarial shedding and histopatopathological picture com ... | 2006 | 17308770 |
| on the origin of the biomphalaria glabrata hemocytes. | a histologic, morphometric and ultrastructural study performed on biomphalaria glabrata submitted to infection with schistosoma mansoni miracidia failed to provide significant evidences that the so-called amebocyte-producing organ (apo) is really the central organ for hemocyte production. in infected snails no general reactive changes appeared in the apo, the mitoses were seen only occasionally, and the possibility of cellular hyperplasia was ruled out by morphometric measurements. under the ele ... | 2006 | 17308772 |
| freshwater snails and schistosomiasis mansoni in the state of rio de janeiro, brazil: vi--noroeste fluminense mesoregion. | in this paper, the last of a series dealing with the survey of freshwater gastropods of the state of rio de janeiro, the results of collections carried out in the noroeste fluminense mesoregion from 2002 to 2005 are presented and revealed the occurrence of 20 species: antillorbis nordestensis; biomphalaria glabrata; b. straminea; b. tenagophila; drepanotrema anatinum; d. cimex; d. depressissimum; d. lucidum; ferrissia sp.; gundlachia ticaga; gundlachia sp.; heleobia sp.; idiopyrgus sp.; lymnaea ... | 2006 | 17308776 |
| activity of praziquantel on in vitro transformed schistosoma mansoni sporocysts. | praziquantel (pzq) is effective against all the evolutive phases of schistosoma mansoni. infected biomphalaria glabrata snails have their cercarial shedding interrupted when exposed to pzq. using primary in vitro transformed sporocysts, labeled with the probe hoechst 33258 (indicator of membrane integrity), and lectin of glycine max (specific for carbohydrate of n-acetylgalactosamine membrane), we evaluated the presence of lysosomes at this evolutive phase of s. mansoni, as well as the influence ... | 2006 | 17308783 |
| interspecific antagonism and virulence in hosts exposed to two parasite species. | co-infection of host organisms by multiple parasite species has evolutionary consequences for all participants in the symbiosis. in this study, we co-exposed aquatic-snails (biomphalaria glabrata) to two of their trematode parasites, schistosoma mansoni and echinostoma caproni. in co-exposed snails, e. caproni prevalence was 63% compared to only 23% for s. mansoni. co-exposed e. caproni-infected snails exhibited reduced fecundity, higher mortality, and higher parasite reproduction (higher virule ... | 2007 | 17400242 |
| effects of aestivation and starvation on the neutral lipid and phospholipid content of biomphalaria glabrata infected with schistosoma mansoni. | the effects of aestivation or starvation on the neutral lipid and phospholipid content of biomphalaria glabrata patently infected with schistosoma mansoni were determined by high-performance thin-layer chromatography-densitometry. infected-aestivated snails were maintained in a moist chamber at 24 +/- 1 c and a relative humidity of 98 +/- 1%. infected-starved snails were maintained in artificial spring water (asw) at 23 +/- 1 c without exogenous food. infected snails (the controls) were maintain ... | 2007 | 17436935 |
| mitotic responses to injected extracts of larval and adult schistosoma mansoni in biomphalaria glabrata: effects of dose and colchicine treatment. | biomphalaria glabrata snails injected with extracts of schistosoma mansoni miracidia, mother sporocyst excretory-secretory product, cercariae, and adults, showed increased mitotic activity in histological sections of the amebocyte-producing organ (apo) relative to water-injected controls. the mitotic response was generally higher to extracts adjusted to 1.0 mg protein/ml than to a 10-fold lower concentration, although in most cases this increase was not statistically significant. colchicine trea ... | 2007 | 17436970 |
| antioxidant gene expression and function in in vitro-developing schistosoma mansoni mother sporocysts: possible role in self-protection. | the ability of the larval forms of schistosoma mansoni to invade and parasitize their molluscan host, biomphalaria glabrata, is determined by a multitude of factors. in this study we sought to elucidate the possible mechanisms by which the invading larvae are able to counteract the potentially harmful oxidative environment presented by the host upon initial miracidial infection. this was attempted by examining the gene expression profile of parasite antioxidant enzymes of the linked glutathione- ... | 2007 | 17445325 |
| high performance column liquid chromatographic analysis of selected carboxylic acids in biomphalaria glabrata patently infected with schistosoma mansoni. | high-performance liquid chromatography (hplc) was used to determine the effects of a patent schistosoma mansoni infection on certain carboxylic acids in the digestive gland gonad complex (dgg) and hemolymph of biomphalaria glabrata. an analysis of dgg samples was done using extraction with 50% locke's solution, cleanup of the extract by anion exchange solid phase extraction (spe), and ion exclusion hplc with ultraviolet detection. hemolymph was applied directly to the spe column. acetic, fumaric ... | 2007 | 17483962 |
| association of bacteria with metacercarial cysts of echinostoma caproni. | echinostoma caproni metacercarial cysts often need to be stored for several months to a year to meet laboratory requirements. this study examined the bacteria associated with encysted metacercariae stored at 4 degrees c. bacterial assemblages from the kidney-pericardial region of uninfected snails and assemblages from the site of metacercarial infection in biomphalaria glabrata were determined. four species of gram-negative rods were isolated and identified from the stored cysts to species or ge ... | 2007 | 17483963 |
| evaluation of the effect of oxamniquine, praziquantel and a combination of both drugs on the intramolluscan phase of schistosoma mansoni. | the activity of oxamniquine (oxa), praziquantel (pzq), and a combination of both drugs was evaluated at the intramolluscan phase of schistosoma mansoni. biomphalaria glabrata snails infected with s. mansoni were treated with 500 mg/kg oxa, 1000 mg/kg pzq or with 250 mg/kg oxa and 500 mg/kg pzq, in association, at the pre-patent and patent phases of infection. the results showed that either treatments with oxa or pzq, alone, at the pre-patent period, delayed the parasite's development, increasing ... | 2007 | 17498638 |
| nimbus (bgi): an active non-ltr retrotransposon of the schistosoma mansoni snail host biomphalaria glabrata. | the freshwater snail biomphalaria glabrata is closely associated with the transmission of human schistosomiasis. an ecologically sound method has been proposed to control schistosomiasis using genetically modified snails to displace endemic, susceptible ones. to assess the viability of this form of biological control, studies towards understanding the molecular makeup of the snail relative to the presence of endogenous mobile genetic elements are being undertaken since they can be exploited for ... | 2007 | 17521654 |
| interplay between host genetic variation and parasite transmission in the biomphalaria glabrata-schistosoma mansoni system. | genetic variability is often predicted to enhance host fitness in the face of parasitism, yet this idea is rarely tested in an experimental setting, particularly with animal hosts. to assess this question, we used a relatively resistant line of snail hosts (biomphalaria glabrata) to generate inbred and outcrossed progeny that were then either exposed or sham-exposed to the trematode parasite, schistosoma mansoni. results showed no difference in prevalence between the groups; however, large diffe ... | 2007 | 17564726 |
| is host-schistosome coevolution going anywhere? | that pathogens and hosts coevolve is a powerful concept with broad theoretical and applied implications spanning from genetic theory to the medical and veterinary sciences, particularly in the context of infectious disease epidemiology. a substantial body of theory has been developed to explore the likelihood and consequences of coevolution, but few empirical studies have been conducted to test these theories, particularly for indirectly-transmitted pathogen-host systems. we initiated replicate ... | 2007 | 17567519 |
| excretory-secretory proteome of larval schistosoma mansoni and echinostoma caproni, two parasites of biomphalaria glabrata. | schistosoma mansoni and echinostoma caproni are two trematode species that use different strategies (mimicry and immunosuppression, respectively) to interfere with the snail innate immune system. parasites excretory-secretory (es) products have been shown to play a key role in these host-parasite immune interactions. however, they remain largely uncharacterized in larval trematodes. we developed a global proteomic approach to characterize the es proteome of s. mansoni and e. caproni primary spor ... | 2007 | 17606306 |
| ki-67 is expressed in multiplying forms of schistosoma mansoni, but not in snail host tissues. | ki-67 is a protein expressed in the nucleus of several species during cell-division, being absent during the go resting phase of the cellular cycle. during attempts to disclose mitosis in the so-called " amebocyte-producing organ " in biomphalaria glabrata infected with schistosoma mansoni, the parasite multiplying forms appeared strongly marked for ki-67, while the snail tissues were completely negative. these data are worth registering to complement general data on ki-67, and to help future st ... | 2007 | 17710314 |
| characterization of immune genes from the schistosome host snail biomphalaria glabrata that encode peptidoglycan recognition proteins and gram-negative bacteria binding protein. | peptidoglycan (pgn) recognition proteins (pgrps) and gram-negative bacteria binding proteins (gnbps) play an essential role in toll/imd signaling pathways in arthropods. the existence of homologous pathways involving pgrps and gnbps in other major invertebrate phyla such as the mollusca remains unclear. in this paper, we report four full-length pgrp cdnas and one full-length gnbp cdna cloned from the snail biomphalaria glabrata, the intermediate host of the human blood fluke schistosoma mansoni, ... | 2007 | 17805526 |
| surface membrane proteins of biomphalaria glabrata embryonic cells bind fucosyl determinants on the tegumental surface of schistosoma mansoni primary sporocysts. | previous observations that in vitro adherence of biomphalaria glabrata embryonic (bge) cells to sporocyst larval stages of schistosoma mansoni was strongly inhibited by fucoidan, a sulfated polymer of l-fucose, suggested a role for lectinlike bge cell receptors in sporocyst binding interactions. in the present investigation, monoclonal antibodies with specificities to 3 major glycan determinants found on schistosomes, lacdinac, fucosylated lacdinac (ldnf), and the lewis x antigen, were used in a ... | 2007 | 17918362 |
| reproductive activity alterations on the biomphalaria glabrata exposed to euphorbia splendens var. hislopii latex. | the reproductive activity of biomphalaria glabrata exposed to euphorbia splendens var. hislopii latex was evaluated. parameters related to fecundity and fertility were observed. the snails were exposed to the ld50 (1 mg/l) of crude latex. at the first week post exposure (p.e.), the egg laying was reduced. after the fourth week p.e., an increase of the number of eggs/snail occurred. the results showed a marked reduction in the hatching of the snails, revealing an interference of latex exposure wi ... | 2007 | 17923993 |
| regulation of hydrogen peroxide release in circulating hemocytes of the planorbid snail biomphalaria glabrata. | biomphalaria spp. serve as obligate intermediate hosts for the human blood fluke schistosoma mansoni. following s. mansoni penetration of biomphalaria glabrata, hemocytes of resistant snails migrate towards the parasite, encasing the larva in a multicellular capsule resulting in its destruction via a cytotoxic reaction. recent studies have revealed the importance of hydrogen peroxide (h(2)o(2)) and nitric oxide (no) in parasite killing [hahn uk, bender rc, bayne cj. killing of schistosoma manson ... | 2008 | 17981329 |
| specific tyrosine phosphorylation induced in schistosoma mansoni miracidia by haemolymph from schistosome susceptible, but not resistant, biomphalaria glabrata. | molecular interplay during snail-schistosome interactions is poorly understood and there is much to discover concerning the effect of snail host molecules on molecular processes in schistosomes. using the biomphalaria glabrata - schistosoma mansoni host-parasite system, the effects of exposure to haemolymph, derived from schistosome-resistant and susceptible snail strains, on protein tyrosine phosphorylation in miracidia have been investigated. western blotting revealed several tyrosine phosphor ... | 2008 | 18053291 |
| molecular determinants of compatibility polymorphism in the biomphalaria glabrata/schistosoma mansoni model: new candidates identified by a global comparative proteomics approach. | the co-evolutionary dynamics that exist in host-parasite interactions sometimes lead to compatibility polymorphisms, the molecular bases of which are rarely investigated. to identify key molecules that are involved in this phenomenon in the schistosoma mansoni/biomphalaria glabrata model, we developed a comparative proteomics approach using the larval stages that interact with the invertebrate host. we used qualitative and quantitative analyses to compare the total proteomes of primary sporocyst ... | 2008 | 18083248 |
| physiological changes and molluscicidal effects of crude latex and milin on biomphalaria glabrata. | euphorbian latex is commonly used as molluscicides and the euphorbia milii latex was reported as most powerful molluscicidal agents. the physiological and lethal effects of the latex components of euphorbia milii, on the intermediate host biomphalaria spp., of the human liver parasite schistosoma mansoni were described in this study. the standard methodologies for testing plant derived molluscicides formulated by world health organisation (who) were followed with some modifications. the young sp ... | 2008 | 18262588 |
| molecular and functional characterization of a tandem-repeat galectin from the freshwater snail biomphalaria glabrata, intermediate host of the human blood fluke schistosoma mansoni. | in the present study, a tandem-repeat type galectin was characterized from an embryonic cell line (bge) and circulating hemocytes of the snail biomphalaria glabrata, intermediate host of the human blood fluke schistosoma mansoni. the predicted b. glabrata galectin (bggal) protein of 32 kda possessed 2 carbohydrate recognition domains, each displaying 6 of 8 conserved amino acids involved in galactoside-binding activity. a recombinant bggal (rbggal) demonstrated hemagglutinating activity against ... | 2008 | 18280060 |
| sublethal effects of ultraviolet b radiation on miracidia and sporocysts of schistosoma mansoni: intramolluscan development, infectivity, and photoreactivation. | schistosoma mansoni occurs in tropical regions where levels of ultraviolet b (uvb; 290-320 nm) light are elevated. however, the effects of uvb on parasite transmission are unknown. this study examines effects of uvb on the miracidia and sporocysts of s. mansoni, focusing specifically on intramolluscan development, infectivity, and the ability to photoreactivate (repair dna damage using visible light). histology revealed that miracidia irradiated with 861 j x m(-2) underwent abnormal development ... | 2007 | 18314673 |
| fibrinogen-bearing protein genes in the snail biomphalaria glabrata: characterization of two novel genes and expression studies during ontogenesis and trematode infection. | all fibrinogen (fbg)-bearing proteins documented to date in the freshwater snail biomphalaria glabrata, the intermediate host of the human blood fluke schistosoma mansoni, possess the same molecular structure; one or two immunoglobin superfamily (igsf) domains at the n-terminus and a fbg domain at the c-terminus (named as fbg-related protein (frep)). here we report two novel genes that encode fbg-bearing proteins from b. glabrata. different from all known freps, the first gene encodes a protein ... | 2008 | 18417215 |
| localization of carbohydrate determinants common to biomphalaria glabrata as well as to sporocysts and miracidia of schistosoma mansoni. | the presence of antigenic carbohydrate epitopes shared by biomphalaria glabrata as well as by the sporocysts and miracidia representing snail-pathogenic larval stages of schistosoma mansoni was assayed by immunohistochemical staining of paraformaldehyde-fixed tissues. to this end, both polyclonal rabbit antiserum raised against soluble egg antigens (sea) of s. mansoni and monoclonal antibodies recognizing the carbohydrate epitopes ldn [galnac(beta1-4)glcnac(beta1-)], f-ldn [fuc(alpha1-3)galnac(b ... | 2008 | 18507884 |
| effects of azinphos-methyl exposure on enzymatic and non-enzymatic antioxidant defenses in biomphalaria glabrata and lumbriculus variegatus. | azinphos-methyl is an organophosphate insecticide used for pest control on a number of food crops in many parts of the world. the oligochaete lumbriculus variegatus and pigmented and non-pigmented specimens of the gastropod biomphalaria glabrata are freshwater invertebrates that have been recommended for contamination studies. recently, it has been shown that l. variegatus worms exhibit a higher cholinesterase (che) activity and a greater sensitivity to in vivo che inhibition by azinphos-methyl ... | 2008 | 18533225 |
| effects of intermediate host genetic background on parasite transmission dynamics: a case study using schistosoma mansoni. | for parasites that require multiple hosts to complete their development, genetic interplay with one host may impact parasite transmission and establishment in subsequent hosts. in this study, we used microsatellite loci to address whether the genetic background of snail intermediate hosts influences life-history traits and transmission patterns of dioecious trematode parasites in their definitive hosts. we performed experimental schistosoma mansoni infections utilizing two allopatric populations ... | 2008 | 18538767 |
| expression profiling and binding properties of fibrinogen-related proteins (freps), plasma proteins from the schistosome snail host biomphalaria glabrata. | a growing body of evidence suggests an important role for fibrinogen-like proteins in innate immunity in both vertebrates and invertebrates. it has been shown that fibrinogen-related proteins (freps), plasma proteins present in the freshwater snail biomphalaria glabrata, the intermediate host for the human blood fluke schistosoma mansoni, are diverse and involved in snail innate defense responses. to gain further insight into the functions of freps, recombinant frep proteins (rfreps) were produc ... | 2008 | 18562576 |
| comparative orestes-sampling of transcriptomes of immune-challenged biomphalaria glabrata snails. | the snail biomphalaria glabrata (gastropoda, mollusca) is an important intermediate host for the human parasite schistosoma mansoni (digenea, trematoda). anti-pathogen responses of b. glabrata were studied towards a better understanding of snail immunity and host-parasite compatibility. open reading frame ests (orestes) were sampled from different transcriptomes of m line strain b. glabrata, 12h post-challenge with escherichia coli (gram-negative), micrococcus luteus (gram-positive) bacteria or ... | 2008 | 18590737 |
| differences in cysteine protease activity in schistosoma mansoni-resistant and -susceptible biomphalaria glabrata and characterization of the hepatopancreas cathepsin b full-length cdna. | biomphalaria glabrata snails are known to display a wide range of susceptibility phenotypes to schistosoma mansoni infection depending on the genetics of both the snail and the invading parasite. evidence exists for a role of hydrolytic enzymes in the defense of molluscs against invading parasites. to elucidate the role of these enzymes in the outcome of infection in the snail, proteolysis was examined in parasite-resistant and -susceptible snails. zymographs of extracts from the whole snail or ... | 2008 | 18605796 |
| disruption of erk signalling in biomphalaria glabrata defence cells by schistosoma mansoni: implications for parasite survival in the snail host. | biomphalaria glabrata is an intermediate snail host for the human blood fluke schistosoma mansoni. to survive in b. glabrata, s. mansoni must suppress the snail's haemocyte-mediated defence response; the molecular mechanisms by which this is achieved remain largely unknown. we report here that s. mansoni excretory-secretory products (esps) attenuate phosphorylation of extracellular signal-regulated kinase (erk) in haemocytes from a b. glabrata strain susceptible to s. mansoni. whole s. mansoni s ... | 2008 | 18619674 |
| a mathematical model of schistosoma mansoni in biomphalaria glabrata with control strategies. | we describe and analyze a mathematical model for schistosomiasis in which infected snails are distinguished from susceptible through increased mortality and no reproduction. we based the model on the same derivation as anderson and may (j. anim. ecol. 47:219-247, 1978), feng and milner (a new mathematical model of schistosomiasis, mathematical models in medical and health science, nashville, tn, 1997. innov. appl. math., vanderbilt univ. press, nashville, pp. 117-128, 1998), and may and anderson ... | 2008 | 18668296 |
| [schistosomiasis in an ecotourism area in minas gerais state, brazil]. | this paper discusses schistosomiasis transmission in são josé da serra, a village with a population of 500 in the county of jaboticatubas, minas gerais state, brazil. the area receives thousands of visitors a year for ecotourism. the study was motivated by a case of acute schistosomiasis involving a couple that spent the 2007 carnival (mardi gras) holiday in the area. stool tests from 268 local residents (53.6% of the population) showed that 35 (13%) were positive for the infection. a comparison ... | 2008 | 18670694 |
| [temporary and permanent breeding sites for biomphalaria in jaboatão dos guararapes, pe]. | a malacological survey of permanent and temporary breeding sites was conducted in the piedade neighborhood of jaboatão dos guararapes, pernambuco, between november 2006 and november 2007, with the aim of determining the malacological fauna at this locality, along with the potential for schistosomiasis mansoni transmission. in addition to biomphalaria glabrata (say, 1818), the molluscs drepanotrema cimex (moricand, 1837), pomacea sp and melanoides tuberculatus (muller, 1774) were collected. among ... | 2008 | 18719804 |
| wild and domesticated animals as reservoirs of schistosomiasis mansoni in brazil. | natural infection with schistosoma mansoni in wild vertebrates and domesticated animals in brazil is described in this review from an epidemiological viewpoint. some species of wild rodents are small-sized animals, with a short expectation of life, a limited territory, and present high infection rates under natural conditions. a successful maintenance of the parasite's life cycle under artificial conditions can be achieved with biomphalaria glabrata. on the other hand, despite showing low natura ... | 2008 | 18722335 |
| molecular characterization and gene expression analysis of a pattern recognition protein from disk abalone, haliotis discus discus. | pattern recognition molecules play an important role in innate immunity by recognizing common epitopes on the surface of invading microorganism. a pattern recognition protein (prp) was isolated from a disk abalone, haliotis discus discus, normalized cdna library. it encodes 420 amino acids (aa) including a 20 aa signal peptide sequence. the mature protein has an estimated molecular mass of 45kda and predicted pi of 5.0. the deduced aa sequence showed greatest homology (50%) with a beta-glucan re ... | 2008 | 18782621 |
| in vitro mitotic responses of the amebocyte-producing organ of biomphalaria glabrata to extracts of schistosoma mansoni. | amebocyte-producing organs (apos) of biomphalaria glabrata were maintained in nonnutritive saline with, or without, extracts of miracidia and adults of schistosoma mansoni, and examined histologically. the hematopoietic cells remained viable and showed measurable mitotic activity for up to 6 days, with little evidence of tissue death. apos accumulated fluid and became swollen by as soon as 24 hr, but no cell exomigration was observed. parasite extracts elicited an increase in the number of divid ... | 2008 | 18973421 |
| controlled chaos of polymorphic mucins in a metazoan parasite (schistosoma mansoni) interacting with its invertebrate host (biomphalaria glabrata). | invertebrates were long thought to possess only a simple, effective and hence non-adaptive defence system against microbial and parasitic attacks. however, recent studies have shown that invertebrate immunity also relies on immune receptors that diversify (e.g. in echinoderms, insects and mollusks (biomphalaria glabrata)). apparently, individual or population-based polymorphism-generating mechanisms exists that permit the survival of invertebrate species exposed to parasites. consequently, the g ... | 2008 | 19002242 |
| simultaneous infection of schistosoma mansoni and s. rodhaini in biomphalaria glabrata: impact on chronobiology and cercarial behaviour. | abstract: | 2008 | 19055722 |
| chemokinetic effect of interleukin-1 beta on cultured biomphalaria glabrata embryonic cells. | previous studies have indicated that a molecule with cytokine activity, possibly an interleukin-1-like (il-1) molecule, plays a role in the killing of larval stages of the blood fluke schistosoma mansoni in the snail host biomphalaria glabrata. the purpose of the present experiment was to test the effects of recombinant-human il-1beta (rhil-1beta) on embryonic b. glabrata (bge) cell motility to determine whether the cells respond to the cytokine. response was measured using a variation of a chem ... | 2009 | 19090650 |
| host-parasite relationship of s. mansoni and b. glabrata. | experiments were conducted to study the host-parasite compatibility of various isolates of biomphalaria glabrata snail and schistosoma mansoni parasite isolates. a series of experiments conducted on 12 s. mansoni isolates have shown a range of infectivity potential for b. glabrata snail and 9 isolates of b. glabrata were found differentially susceptible to infection with s. mansoni trematode parasite. | 2007 | 19093502 |
| biomphalaria glabrata transcriptome: cdna microarray profiling identifies resistant- and susceptible-specific gene expression in haemocytes from snail strains exposed to schistosoma mansoni. | biomphalaria glabrata is an intermediate snail host for schistosoma mansoni, one of the important schistosomes infecting man. b. glabrata/s. mansoni provides a useful model system for investigating the intimate interactions between host and parasite. examining differential gene expression between s. mansoni-exposed schistosome-resistant and susceptible snail lines will identify genes and pathways that may be involved in snail defences. | 2008 | 19114004 |
| flow cytometry analysis of the circulating haemocytes from biomphalaria glabrata and biomphalaria tenagophila following schistosoma mansoni infection. | aiming to further characterize the haemocyte subsets in biomphalaria snails, we have performed a detailed flow cytometric analysis of whole haemolymph cellular components using a multiparametric dual colour labelling procedure. ethidium bromide/acridine orange fluorescence features were used to first select viable haemocytes followed by flow cytometric morphometric analysis based on the laser scatter properties (forward scatter-fsc and side scatter-ssc). our findings demonstrated that b. glabrat ... | 2009 | 19126270 |
| revised karyotyping and gene mapping of the biomphalaria glabrata embryonic (bge) cell line. | the fresh water snail biomphalaria glabrata (2n=36) belongs to the taxonomic class gastropoda (family planorbidae) and is integral to the spread of the human parasitic disease schistosomiasis. the importance of this mollusc is such that it has been selected as a model molluscan organism for whole genome sequencing. in order to understand the structure and organisation of the b. glabrata's genome it is important that gene mapping studies are established. thus, we have studied the genomes of two b ... | 2009 | 19133265 |
| community diversity reduces schistosoma mansoni transmission, host pathology and human infection risk. | global biodiversity loss and disease emergence are two of the most challenging issues confronting science and society. recently, observed linkages between species-loss and vector-borne infections suggest that biodiversity may help reduce pathogenic infections in humans and wildlife, but the mechanisms underlying this relationship and its applicability to a broader range of pathogens have remained speculative. here, we experimentally evaluated the effects of host community structure on transmissi ... | 2009 | 19203926 |
| transcriptome analysis of schistosoma mansoni larval development using serial analysis of gene expression (sage). | summary: infection of the snail, biomphalaria glabrata, by the free-swimming miracidial stage of the human blood fluke, schistosoma mansoni, and its subsequent development to the parasitic sporocyst stage is critical to establishment of viable infections and continued human transmission. we performed a genome-wide expression analysis of the s. mansoni miracidia and developing sporocyst using long serial analysis of gene expression (longsage). five cdna libraries were constructed from miracidia a ... | 2009 | 19265565 |
| thai koi-hoi snail dish and angiostrongyliasis due to angiostrongylus cantonensis: effects of food flavoring and alcoholic drink on the third-stage larvae in infected snail meat. | human infection with the rat lungworm angiostrongylus cantonensis (parastrongylus cantonensis) in thailand, especially in the northeastern region, is associated with the habit of eating koi-hoi, which contains raw snail meat. infection results from the snails being carriers of the larval parasite. the present study was conducted to assess the effect of food flavorings in koi-hoi, alcohol, and exposure time of the two variable on the infective larvae of a. cantonensis. infected biomphalaria glabr ... | 2009 | 19272010 |
| behaviour of albino and melanic variants of biomphalaria glabrata say, 1818 (mollusca: planorbidae) following infection by schistosoma mansoni sambon, 1907. | the behaviour of the albino and melanic variants of biomphalaria glabrata of belo horizonte (mg. brazil) was studied comparatively, in terms of their respective susceptibilities to infection by schistosoma mansoni of the same origin, through observation of the elimination of cercariae for a three-month period and the calculation of mortality and infection rates, in control and in infected snails. the number of amoebocytes, granulocytes and hyalinocytes in the circulating hemolymph during differe ... | 2009 | 19347168 |
| effects of host outcrossing on the interaction between an aquatic snail and its locally adapted parasite. | in this study, we investigated the interaction between host outcrossing and infection in the biomphalaria glabrata-schistosoma mansoni system. snails collected from three susceptible isofemale lines were mated with either siblings or snails recently derived from a field site in brazil. resulting inbred and outcrossed progeny were then exposed to s. mansoni larvae and monitored for a 10-week period. interestingly, all snails exhibited equal susceptibility whether they were the result of inbreedin ... | 2009 | 19352708 |
| effects of uvb on interactions between schistosoma mansoni and biomphalaria glabrata. | ultraviolet b (uvb, 280-315nm) radiation is detrimental to both of larvae of the digenetic trematode schistosoma mansoni and its snail intermediate host, biomphalaria glabrata. we explored effects of uvb on three aspects of the interaction between host and parasite: survival of infected snails, innate susceptibility and resistance of snails to infection, and acquired resistance induced by irradiated miracidia. snails infected for 1 week showed significantly lower survival than uninfected snails ... | 2009 | 19375430 |
| bio-active compounds from euphorbia cornigera boiss. | euphorbia cornigera boiss. (euphorbiaceae) roots extracted in various organic solvents were tested against biomphalaria glabrata snails as molluscicide using bayluscide as a control. among these, acetone extract was found to be the most active (lc(50)=17.5 microg l(-1)) as compared to bayluscide. the application of hplc fractionation yielded ten (1-10) n-(2-aminobenzoyl)anthraniloy esters. structure and the relative configuration of all the compounds were established through spectroscopic (uv, i ... | 2009 | 19376614 |
| nitric oxide production by biomphalaria glabrata haemocytes: effects of schistosoma mansoni esps and regulation through the extracellular signal-regulated kinase pathway. | abstract: | 2009 | 19386102 |
| successful parasitism of vector snail biomphalaria glabrata by the human blood fluke (trematode) schistosoma mansoni: a 2009 assessment. | schistosomiasis, caused by infections by human blood flukes (trematoda), continues to disrupt the lives of over 200,000,000 people in over 70 countries, inflicting misery and precluding the individuals' otherwise reasonable expectations of productive lives. infection requires contact with freshwater in which infected snails (the intermediate hosts of schistosomes) have released cercariae larvae. habitats suitable for the host snails continue to expand as a consequence of water resource developme ... | 2009 | 19393158 |
| schistosomin from the snail biomphalaria glabrata: expression studies suggest no involvement in trematode-mediated castration. | by inhibiting reproductive hormones, the neuropeptide schistosomin produced by the snail lymnaea stagnalis plays an essential role in parasitic castration mediated by the schistosome parasite trichobilharzia ocellata during late stage infection. here we report on the presence and expression of schistosomin in the snail biomphalaria glabrata, a prominent intermediate host of the parasite schistosoma mansoni, one of the causative agents of human schistosomiasis. the deduced amino acid (aa) sequenc ... | 2009 | 19393164 |