bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population biology ofPomphorhynchus laevisin brown trout from two lakes in the west of Ireland
Authors: Molloy S. , Holland C. , O'Regan M. 
Published: June 2009

AbstractSince Ireland is the only country in whichPomphorhynchus laevis(Acanthocephala) uses brown trout(Salmo trutta) as its preferred definitive host, the population biology of the parasite in this host was investigated thus enabling a comparison to be made with data collected onP laevisfrom other hosts, particularly the cyprinids, chub and barbel. Over a period of 12 months, 549 brown trout were caught from two lakes, Lough Feeagh and Bunaveela Lake, in the Burrishoole River system, Co. Mayo, Ireland. The parasite component community was dominated by a single species,P laevis. Fifty eight percent of the trout sample were infected with the acanthocephalan and the mean abundance (± SD) was 3.1 ± 5.1. The relationships between the prevalence and abundance ofP laevisand season and site of host capture and host age and sex were explored. As single factors none of these parameters emerged as significant contributors to changes in parasite abundance although some interaction terms proved to the significant. A random sample of over 700P laevisparasites were subjected to further investigation and their size, position in the intestine and maturity status are described. Parasites attained an average weight of 7 mg and occupied the posteriad positions within the fish intestine(77%). Parasites from this sample of Irish brown trout attained a similar average size to those found in chub and barbel from England. 42.3% of the total parasites examined contained ovarian balls only and 17% contained fully mature acanthors. Therefore only a moderate proportion of female worms contained mature acanthors in these trout whereas the majority of worms recovered from a sample of chub were gravid. Utilizing a logistic regression model, parasite size, season, and site of host capture emerged as particularly significant factors which contribute to whether a parasite contains mature eggs.
Ultrastructure of the male reproductive system in a rumen amphistome Cotylophoron cotylophorum
Authors: Sharma P.N. , Swarnakar G. , Hanna R.E.B. 
Published: June 2009

AbstractThe ultrastructure of various regions of the male reproductive tract and the prostate gland of Cotylophoron cotylophorum (Trematoda: Digenea) is described. The internal lining of the entire male duct system is syncytial in nature, and regional variation is quite evident. The syncytial epithelium of the vas deferens and seminal vesicle is very thin, flat and lamellate and the lumen is packed with spermatozoa. In the pars musculosa (PM) the syncytium is also flat but lamellae are sparsely distributed and anastomosed at places to form loops. The syncytium of the PM is invested by several layers of circular and longitudinal muscle. The pars prostatica (PP) is lined by an uneven but moderately thick syncytial epithelium with nuclei projecting into the lumen. The syncytium bears numerous very long lamellae. The ejaculatory duct epithelium is devoid of lamellae. It is even and moderately thick throughout. The prostate gland cells are uneven in outline and bear long ducts which open into the lumen of the PP. They show an ultrastructural organization suggestive of protein secretion.
Ultrastructural observations on the redial tegument of Paramphistomum epiclitum from the planorbid snail, Indoplanorbis exustus
Authors: Dunn T. S. , Dang P. H. , Mattison G. , Hanna R. E. B. , Nizami W. A. 
Published: June 2009

ABSTRACTThe morphology of the tegument in the redia of Paramphistomum epiclitum (Digenea: Paramphistomidae) resembles that shown by most larval and adult digeneans; an outer surface syncytium is in continuity with the cytoplasm of in-sunken, nucleated cytons. Although tegumental cytons usually contain a single nucleus, some display up to six nuclei. The tegumental syncytium lining the pharynx of P. epiclitum rediae lack underlying cytons. The apical membrane of the tegument is elaborated by folds and microvilli, which presumably facilitate uptake of nutrients and/or exchange of ions involved in osmoregulation. A single type of secretory body, resulting from the fusion of smaller vesicles produced at Golgi complexes in the cytons, occurs throughout the tegument. Uniciliate sensory receptors occur in the surface syncytium particularly around the oral opening.
Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus
Authors: Dunn T. S. , Dang P. H. , Hanna R. E. B. , Nizami W. A. 
Published: June 2009

ABSTRACTCercariae develop from individual germinal cells occurring freely within the posterior body cavity of rediae. Individual germinal cells give rise to a germinal ball which becomes enveloped by increasing numbers of cytoplasmic extensions originating from specialized parenchyma-like cells, termed nursc cells. Up to eight cytoplasmic layers of nurse cells invest larger germinal balls. These layers may provide mechanical support for developing embryos and/or play a role in the provision of nutrients to them. The cercarial tegument develops from superficially located somatic cells in the germinal ball. Cytoplasmic extensions of presumptive tegumental cells fuse laterally to form a syncytial layer beneath the encapsulating nurse cell layers. As the cercarial tegument differentiates further, the cytoplasm of the nurse cell layers becomes vacuolated and ultimately these layers degenerate. The surface tegumental syncytia of intra-redial cercariae and newly released extra-redial cercariae are nucleated. Separate subtegumental perikarya develop with further differentiation of extra-redial cercariae.
Mitotic chromosomes of Sphaerostomum bramae (Müller, 1776) Szidat, 1944
Authors: Petkevičiūtė R. , Stanevičiūtė G. , Kiselienė V. 
Published: June 2009

AbstractKaryometrical analysis of conventional Giemsa-stained mitotic chromosomes of parthenitae of Sphaerostomum bramae (Trematoda: Opecoelidae) was carried out. The karyotype displays a typical ‘plagiorchiid’ pattern with 22 chromosomes in a diploid set including a first pair of large metacentric elements. Chromosomes with medially or submedially located centromeres prevail in the karyotype; only chromosomes 7 and 9 are subtelocentric. With the data now available, close karyological affinity was noted between S. bramae, the representative of the family Opecoelidae, and other karyologically studied species of some families in the order Plagiorchiiformes: Troglotrematidae, Plagiorchiidae, Prosthogonimidae, Lecithodendriidae and Telorchiidae.
Adherence of carp leucocytes to adults and cercariae of the blood flukeSanguinicola inermis
Authors: Richards D.T. , Hoole D. , Lewis J.W. , Ewens E. , Arme C. 
Published: June 2009

AbstractLive adult and cercarial stages ofSanguinicola inermisPlehn, 1905 (Trematoda: Sanguinicolidae) were maintainedin vitroin the presence of carp (Cyprinus carpioL.) leucocytes. Cells and parasites were fixed at intervals from 0.25 to 48 h and examined using light microscopy, SEM and TEM. Within 12 h of exposure, leucocytes were found attached to cercariae although, by 24 h, fewer cells were found attached to postcercarial, juvenile adult stages that had shed their tails. Neutrophils and macrophages were found attached to the damaged tegument of cercariae that had not transformed by 48 h. Few cells were attached to the tegument of adult flukes that were alive when fixed. However, there was extensive tegumental damage and numerous cells were attached to adult flukes that had died before fixation. The results are discussed with reference to parasite survival within the vascular system of the host.
Infectivity and the cercarial tail chamber in Proterometra macrostoma
Authors: Braham G.L. , Riley M.W. , Uglem G.L. 
Published: June 2009

AbstractThe tail chamber's role in the survival and infectivity of Proterometra macrostoma (Digenea: Azygiidae) was investigated. Intact cercariae and cercarial bodies dissected from tails were incubated for 14 h in artificial pond water (APW) and cercarial infectivity was assessed in laboratory infections of the bluegill sunfish, Lepomis macrochirus. Although most cercariae stopped swimming and settled to the bottom after 14 h, survival and infectivity of bodies from intact cercariae did not decrease significantly during this period. All isolated bodies survived in APW, but they were 54% less infective. By contrast, infectivity of isolated bodies did not decrease significantly in an artificial snail saline. The results indicate that maximum infectivity in P. macrostoma is sustained throughout the swimming phase because of the tail chamber which protects the body from the effects of osmotic stress.
Developmental changes in the tegument of four microphallid metacercariae in their second (crustacean) intermediate hosts
Authors: Galaktionov K.V. , Malkova I.I. , Irwin S.W.B. , Saville D.H. , Maguire J.G. 
Published: June 2009

AbstractThe morphology of the tegument of four microphallid metacercariae from the stage of invasive cercariae to their maturation as encysted metacercariae inside their crustacean second intermediate hosts is described. The tegument of the metacercariae developed surface lamellae and projections which, along with coated vesicles in the surface syncytium, indicated that the tegument had an absorptive function. The disappearance of secretory granules from the tegument at the same time as the appearance of the first cyst wall suggested that the tegument had a role in primary cyst production. Following this, the metacercariae continued to grow and seemingly retained their absorptive ability. The tegument was also involved in the transport of material into the perimetacercarial lumen prior to its eventual inclusion in the developing inner cyst layers. It appeared that this material originated in tegumental cells located amongst the parenchymal cells beneath the tegumental syncytial layer. On completion of the secondary cyst layers there was a gradual degeneration of structures associated with absorption and a progressive accumulation of dense discoid granules traceable to underlying tegumental cells. All four microphallid species (Maritrema arenaria,M. subdolum,Levinseniella brachysomaandMicrophallus claviformis) demonstrated the same developmental pattern but the period spent in each stage differed depending on the time spent migrating to encystment sites. The pattern of tegumental development described is thought to be applicable to all microphallid metacercariae and possibly to other metacercariae which undergo growth and development in their second intermediate hosts.
Natural infection of the calanoid crustacean Epischura baicalensis by procercoids of Proteocephalus sp. in Listvenichnyi Bay, Lake Baikal
Authors: Rusinek O.T. , Bakina M.P. , Nikolskii A.V. 
Published: June 2009

AbstractNatural infection of the plankton Epischura baicalensis Sars (Calanoida: Temoridae) by procercoids of the genus Proteocephalus in Lake Baikal is analysed in detail. Over one year Epischura was infected by procercoids of proteocephalids at a prevalence of 0.13% (in Listvenichnyi Bay, South Baikal). Male E. baicalensis were infected more (0.39%). The number of procercoids of genus Proteocephalus was 2.7 specimens/m3. The largest number of procercoids was found in females (1.26), the least in the third copepodid stage (0.03 specimens/m3). Because of the close ecological contacts between E. baicalensis and Coregonus autumnalis migratorius it is probable that E. baicalensis is infected by P. exiguus, the species usually found in C. a. migratorius (Zaika, 1965). The parasite lives for about 8 months in the winter-spring Epischura generation and about 10 months in the summer generation.
Characterization of Spanish Trichinella isolates by random amplified polymorphic DNA (RAPD)
Authors: Rodríguez E. , Nieto J. , Castillo J.A. , Gárate T. 
Published: June 2009

AbstractThe random amplified polymorphic DNA (RAPD) assay was used to find molecular markers able to distinguish Trichinella spiralis from T. britovi, the two recognized Spanish Trichinella species. Fourteen Spanish Trichinella isolates, as well as reference Trichinella isolates representing the five species T. spiralis (T1), T. nativa (T2), T. britovi (T3), T. pseudospiralis (T4) and T. nelsoni (T7) and the three other taxa Trichinella T5, Trichinella T6 and Trichinella T8 of the genus, were characterized by RAPD using both purified and crude DNAs from infective muscle larvae (ML) and seven arbitrary primers. Three primers yielded diagnostic RAPD markers for the Spanish T. spiralis and T. britovi isolates as well as for the Trichinella reference isolates analysed, and in the case of crude DNAs the results were obtained in few hours. In addition, the species-specificity of the diagnostic RAPD markers from Spanish Trichinella isolates was studied by cross-hybridization assays. These assays confirmed that the selected diagnostic DNA fragments were not species-specific, but showed potential differences in the copy number among the examined Trichinella genetic clusters.
Morphological comparison and identification of metacercariae in the ‘pygmaeus’ group of microphallids, parasites of seabirds in western palaearctic regions
Authors: Saville D.H. , Galaktionov K.V. , Irwin S.W.B. , Malkova I.I. 
Published: June 2009

AbstractThis study compares the metacercariae of a ‘pygmaeus’ microphallid discovered inLittorina saxatilisfrom the coast of Northern Ireland with the metacercariae ofMicrophallus piriformesandM. pygmaeusfrom the same species of gastropod mollusc from Arctic Russia. Light and scanning electron microscopy were used to provide morphometric and surface details for descriptions of the organisms concerned. Comparison and statistical analysis of the results established that the species from Northern Ireland wasM. piriformesand notM. pygmaeusas had previously been assumed. It dearly indicates the need for critical assessment of the accuracy of literature dealing with the occurrence of ‘M. pygmaeus’ in both intermediate and final hosts.
Infectivity of a Cambodian isolate of Schistosoma mekongi to Neotricula aperta from northeast Thailand
Authors: Attwood S.W. , Kitikoon V. , Southgate V.R. 
Published: June 2009

AbstractAll three strains of Neotricula aperta (Gastropoda: Pomatiopsidae) sampled from populations in northeast Thailand were found to be compatible with a Schistosoma mekongi isolate from Kratié District, eastern Cambodia. The infection rates were: 3.0%, α-strain; 6.0%, β-strain; and 20.5%, γ-strain. The greater infectivity to the γ-strain, over both the α- and β-strains, was statistically significant. Comparisons of infectivity patterns for the Kratié isolate, with those described in earlier studies using S. mekongi isolates from southern Laos, revealed differences among the strains. The γ-strain of N. aperta is responsible for endemic transmission of human schistosomiasis in southern Laos and at Kratié. Consequently, the findings of this study are of use in the prediction of changes in the distribution of Mekong schistosomiasis, particularly its introduction to northeast Thailand from the neighbouring countries, Cambodia and Laos.
Glutathione-s-transferase is an important antigen in the eel nematodeAnguillicola crassus
Authors: Nielsen M.E. , Buchmann K. 
Published: June 2009

AbstractDifferent organs and secretions/excretions of the swimbladder parasite,Anguillicola crassus(Nematoda), were tested for the presence of antigens to the humoral immune response previously detected in the European eel,Anguilla anguilla. Proteins from different fractions ofAnguillicola crassuswere separated using SDS–PAGE (sodium-dodecyl-sulphate polyacrylamide-gel electrophoresis) under reducing conditions and electroblotted onto nitrocellulose membranes. Infected eels showed a specific antibody response to a 43 kDa antigen in the cuticle and towards two gonad antigens around 34 and 43 kDa. In protein released from the worms, two secretory/excretory antigens of approximately 28 kDa were found. The secretion/excretion rate of protein from the parasite to the surroundings was determined. Subsequently, an ELISA system was established applying these antigens as the first layer of coating. Furthermore, antigens fromAnguillicola crassuswere examined for the presence of glutathione-s-transferase (GST) using a specific antibody against GST. The antigens were found to be subunits of GST.
Filarial DNA and its interaction with polyamines and antifilarial drugs
Authors: Pandya U. , Saxena J.K. , Shukla O.P. 
Published: June 2009

AbstractThe interaction of DNA from filarial parasite Setaria cervi with polyamines was monitored by melting temperature (Tm) profile, condensation and B to Z DNA transition and compared with DNA of Escherichia coli, Micrococcus luteus and calf thymus having different GC content. Polyamines, viz. spermine and spermidine, stabilized the secondary structure of all DNAs as indicated by increase in Tm value. UV absorption studies indicated B to Z DNA transition in the presence of polyamines. The amount of polyamines required for B to Z transition was dependent upon base composition of DNA and charge of the polyamine. Filarial DNA (AT rich) required six times higher concentration of spermine as compared to GC rich DNA for B to Z DNA transition. Spermidine was not effective in causing transition of S. cervi DNA even at Spd:DNA-P ratio of 20. The antifilarial compound suramin significantly decreased melting temperature of filarial DNA as compared to GC rich DNAs of other parasites. Suramin adversely affected condensation and B to Z DNA transition of various DNAs but prior addition of polyamines protected the DNAs from the destabilizing effect of suramin.
Proteinases secreted byFasciola hepatica: time course of the inhibitory effect of serum from experimentally infected rabbits demonstrated by gelatin-substrate polyacrylamide gel electrophoresis
Authors: Piacenza L. , Acosta D. , Dowd A. , McGonicle S. , Dalton J. , Carmona C. 
Published: June 2009

AbstractFasciola hepaticasecretes proteolytic enzymes to aid it to penetrate and migrate through the host tissues. Two of these proteinases have been purified and shown to be cathepsin L-like, and are termed, CL1 (27.5 kD) and CL2 (29 kD). The immunogenicity of these proteinases was investigated over the course of an experimental infection and following drug treatment. Four groups of rabbits were studied: group 1: orally infected with 50 metacercariae; group 2: infected and treated 8 weeks after infection; group 3: infected, treated at week 8 and reinfected at week 13 and group 4: non-infected control group. Sera were collected weekly from each group until week 20 postinfection. CL1 and CL2 were incubated with the different sera and then analysed by gelatin substrate polyacrylamide gel electrophoresis (GS-PAGE). Analysis of groups 1, 2 and 3 showed that CL1 and CL2 neutralizing antibodies appear at week 5 post-infection. In group 1, these remained throughout the 20 weeks of infection. In group 2, neutralizing antibodies disappeared at week 13, that is, 5 weeks after anti-Fasciolatreatment. In group 3, CL1 and CL2 neutralizing antibodies disappeared at week 13 but reappeared by week 15, that is 2 weeks after reinfection. Pooled sera from group 4, showed no inhibitory capacity. ELISA results using CL1 and CL2 as antigen, correlate very well with the inhibitiory time course observed by GS-PAGE. These results suggest that purified cathepsin Ls are antigenic molecules recognized early in the infective process and capable of inducing a specific humoral response, strong enough to neutralize, at least partially, their enzymatic activity.
Some histochemical characteristics of the mucous microenvironment in four salmonids with different susceptibilities to gyrodactylid infections
Authors: Buchmann K. 
Published: June 2009

AbstractSkin mucous cells and mucus from four salmonids (rainbow trout, brown trout, Conon salmon, Iijoki salmon) with different susceptibilities to infection withGyrodactylus derjaviniandG. salariswere partly characterized by cytochemistry, immunoblotting and immunocytochemistry. Mucous cell densities in various fin types were partly correlated with resistance to infection withG. derjavinibut not withG. salaris. Lectin binding assays indicated slight differences in carbohydrate composition of mucus from the four salmonids but serum antigens specific for salmonids were found in mucus from all of them. Antisera against salmon immunoglobulin and rainbow trout complement factor C3 reacted with mucus from all of the salmonids but not with mucus from phylogenetically unrelated fish. Antisera raised against ACTH reacted with mucus components from rainbow trout, brown trout and Conon salmon but not with mucus from Iijoki salmon. These findings are discussed in relation to the host specificity of ectoparasites and susceptibility to infection.
Characterization ofFasciola hepaticaredial generations by morphometry and chaetotaxy under experimental conditions
Authors: Augot D. , Rondelaud D. , Dreyfuss G. , Cabaret J. , Bayssade-Dufour C. , Albaret J.L. 
Published: June 2009

AbstractMorphometric and chaetotactic studies were carried out on the body and cephalic regions of the rediae ofFasciola hepatica(Trematoda: Fasciolidae) in order to precisely identify the different redial generations of this trematode inLymnaea truncatulaunder experimental infection. At day 49 post-exposure at 20°C, the length of the redia was significantly higher in the first group of the first generation (R1a) compared with successive generations, R1b, R2a and R2b/R3a. The width of the body was similar in the R1a, R1b, and R2a rediae, but was significantly lower in the R2b/R3a groups. The intrapharyngeal cavity of R1a rediae was significantly wider compared with the R1b, R2a, and R2b/R3a groups, whereas the pharyngeal wall was significantly thicker in the R2b/R3a rediae compared with the R1b and R2a groups. Four other measurements, namely the maximum length and width of the pharynx, diameter of the mouth, and width of intestine, also showed significant variations in relation to pharyngeal morphology and age of infection. Discriminant analysis based on these measurements demonstrated that 98% of the rediae were readily categorized into the four groups identified. The number of perioral sensillae ranged from 126 to 160 but a significant difference was only noted between the mean values of the first generation and those of the group R2b/R3a. From these parameters, the maximum width of the pharyngeal lumen was found to be the best characteristic in the identification of the redial generations.
The structuring process of the macroparasite community of an experimental population of Cichlasoma urophthalmus through time
Authors: Vidal-Martinez V.M. , Kennedy C.R. , Aguirre-Macedo M.L. 
Published: June 2009

AbstractThe structuring process of the macroparasite community of caged Cichlasoma urophthalmus was studied over time using sentinel fish. Three thousand uninfected cichlids were stocked in floating cages introduced into a quarry in which a wild population of the same species was present. Caged and wild cichlids were sampled monthly over 6 and 7 months, respectively. Seventeen macroparasite species were found in the wild C. urophthalmus population, ten of which were detected in the caged population after 6 months. Early infections were by those species that were more frequent and abundant in the wild population, while helminths with a low prevalence and abundance in the wild appeared later in the caged fish population. The results suggested that the structuring process of the macroparasite community of caged C. urophthalmus followed a predictable pattern, in which those species that were most frequent and abundant in the wild were the first to establish in sentinel fish.