Search results for "Biomphalaria"
showing 10 items of 16 documents
3D-Ultrastructure, Functions and Stress Responses of Gastropod (Biomphalaria glabrata) Rhogocytes
2014
Rhogocytes are pore cells scattered among the connective tissue of different body parts of gastropods and other molluscs, with great variation in their number, shape and size. They are enveloped by a lamina of extracellular matrix. Their most characteristic feature is the "slit apparatus", local invaginations of the plasma membrane bridged by cytoplasmic bars, forming slits of ca. 20 nm width. A slit diaphragm creates a molecular sieve with permeation holes of 20×20 nm. In blue-blooded gastropods, rhogocytes synthesize and secrete the respiratory protein hemocyanin, and it has been proposed-though not proven-that in the rare red-blooded snail species they might synthesize and secrete the he…
Biomphalaria Snails and Larval Trematodes
2011
Biomphalaria snails and larval trematodes , Biomphalaria snails and larval trematodes , کتابخانه مرکزی دانشگاه علوم پزشکی تهران
Effects of Nonschistosome Larval Trematodes on Biomphalaria Snails
2010
This chapter examines the most salient literature on the development of nonschistosome larval digeneans in Biomphalaria spp. (members of the superfamilies Clinostomoidea, Diplostomoidea, Echinostomatoidea, Paramphistomoidea, and Pronocephaloidea). For this purpose, the general biology of the nonschistosome trematode species that use Biomphalaria spp. as intermediate hosts are analyzed. Thereafter, the main features of these parasitic infections are studied with particular emphasis on topics such as the effect of the infections on the snail, the antagonism and/or competition between different digenean species in the snail, the immunology of the infection, and the genomic and proteomic a…
Acetylcholine-binding protein in the hemolymph of the planorbid snail Biomphalaria glabrata is a pentagonal dodecahedron (60 subunits).
2012
Nicotinic acetylcholine receptors (nAChR) play important neurophysiological roles and are of considerable medical relevance. They have been studied extensively, greatly facilitated by the gastropod acetylcholine-binding proteins (AChBP) which represent soluble structural and functional homologues of the ligand-binding domain of nAChR. All these proteins are ring-like pentamers. Here we report that AChBP exists in the hemolymph of the planorbid snail Biomphalaria glabrata (vector of the schistosomiasis parasite) as a regular pentagonal dodecahedron, 22 nm in diameter (12 pentamers, 60 active sites). We sequenced and recombinantly expressed two ∼25 kDa polypeptides (BgAChBP1 and BgAChBP2) wit…
Kinetics of antibodies and antigens in serum of mice experimentally infected with echinostoma caproni (trematoda: echinostomatidae)
2005
The present study reports on the kinetics of antibodies and antigens in serum of mice experimentally infected with 75 metacercariae of Echinostoma caproni during the first 12 wk postinfection (wpi). Antibody titers in the serum of mice were determined by an indirect enzyme-linked immunosorbent assay (ELISA) using excretory/secretory (ES) antigens of E. caproni. The early detection of antibodies against ES antigens of E. caproni is feasible using indirect ELISA. Mice developed significant antibody responses at 2 wpi, and the values progressively increased until the end of the experiment. This may be related to the intestinal absorption of adult worm antigens that induces humoral responses. T…
Development and pathology of echinostoma caproni in experimentally infected mice
2007
In the present article, several parasitological features of mice, each experimentally infected with 75 metacercariae of Echinostoma caproni (Trematoda: Echinostomatidae), were studied during the first 12 wk postinfection. Moreover, the early pathological responses also were analyzed and compared with data previously published on other host species of E. caproni to gain further insight into the factors determining worm rejection or establishment of chronic infections. The results obtained show that the pattern of E. caproni infection in mice is consistent with a highly compatible host–parasite system. This combination is characterized by a high worm establishment, high egg output, and long s…
Screening trematodes for novel intervention targets: a proteomic and immunological comparison of Schistosoma haematobium, Schistosoma bovis and Echin…
2011
SUMMARYWith the current paucity of vaccine targets for parasitic diseases, particularly those in childhood, the aim of this study was to compare protein expression and immune cross-reactivity between the trematodes Schistosoma haematobium, S. bovis and Echinostoma caproni in the hope of identifying novel intervention targets. Native adult parasite proteins were separated by 2-dimensional gel electrophoresis and identified through electrospray ionisation tandem mass spectrometry to produce a reference gel. Proteins from differential gel electrophoresis analyses of the three parasite proteomes were compared and screened against sera from hamsters infected with S. haematobium and E. caproni fo…
Echinostoma caproni: Differential tegumental responses to growth in compatible and less compatible hosts
2010
Abstract The topography of the tegument of Echinostoma caproni adults collected from high (mice) and low (rats) compatible hosts was compared by SEM. In the oral (OS) and the ventral sucker (VS) areas, a worm age–host species interaction was found with regard to the density of spines. There was a decrease in the density of spines in the adults collected from mice, whereas an increase occurred in the OS area in worms from rats over time. The tegumentary spines in adults from mice became larger and blunter. Some spines from the VS area in adults from mice at 4 wpi were multipointed. The spines of adults from rats were sharper, not covered by the tegument and no multipointed spines were observ…
A potential snail host of schistosomiasis in Bolivia: Biomphalaria amazonica paraense, 1966
2002
Biomphalaria amazonica Paraense, 1996 was collected from a permanent pond in the outskirts of the Bolivian city of Santa Cruz. Identification of the collected specimens was made by comparison with the original description of the species and with topotypic material in the collection of Instituto Oswaldo Cruz. Phylogenetic analysis confirmed that these Bolivian specimens belong to B. amazonica.
New Biologically Active Triterpene-Saponins fromRandia dumetorum
1990
Two new triterpene-saponins, 3-O-[O-beta-D-glucopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----3)-( beta- D-glucuronopyranosyl)]oleanolic acid (1), 3-O-[O-beta-D-glucopyranosyl-(1----6)-O-beta-D-glucopyranosyl- (1----3)-(beta-D-glucuronopyranosyl)]oleanolic acid (2) together with five known saponins (3-7) were isolated from the methanolic extract of the fruits of Randia dumetorum (Retz) Lam. (Rubiaceae). Their structures were established on the basis of chemical and spectral data. The compounds 1, 3, 4, 5 were found to enhance significantly the proliferation of human lymphocytes in vitro. The crude saponin fraction showed haemolytic, molluscicidal, and immunostimulating activities.