bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paramyosin isoforms ofSchistosoma mansoniare phosphorylated and localized in a large variety of muscle types
Authors: Schmidt J. , Bodor O. , Gohr L. , Kunz W. 
Published: June 2009

SUMMARYParamyosin, although a widely distributed muscle component among invertebrates, has hitherto not clearly been shown to occur in the muscles of schistosomes. Instead, it has been reported to occur in the tegument. In the present study, a specific antibody reacting with each of 10 isoforms of paramyosin was used for light microscopical immunolocalization in sections ofSchistosoma mansoni. Specimens were fixed by a new method to immobilize antigens with uranyl acetate–trehalose–methanol. In cercariae, schistosomula, and adults, the circular and longitudinal muscles of the body wall, the dorsoventral muscles and those surrounding the gut and the pharynx as well as the fast moving cross-striated muscles of the tail of cercariae intensely reacted with the antibody. However, neither immunohistologically nor on Western blots of isolated tegument, were indications found for the presence of paramyosin in the tegument.In vivophosphorylation and binding of anti-phospho-tyrosine and anti-phospho-serine antibodies show phosphorylation of paramyosin which probably is responsible for the generation of the isoforms.
Intestinal parasite burden in five troops of olive baboons (Papio cynocephalus anubis) in Gombe Stream National Park, Tanzania
Authors: Müller-Graf C. D. M. , Collins D. A. , Woolhouse M. E. J. 
Published: June 2009

SUMMARYA cross-sectional parasitological study of a population of wild olive baboons (Papio cynocephalus anubis), consisting of 5 troops, was conducted in Gombe Stream National Park. Baboons were individually recognizable. Information on age, sex, troop membership, reproductive status, social rank and life-history of each individual baboon could be related to parasite infection. Seven helminth taxa and 2 protozoan taxa were found. All baboons were parasitized by at least 1 taxon. Distributions of helminths were aggregated among hosts. There were significant differences among troops in the prevalence of all but 2 of the recorded helminths. Age had a significant impact on the prevalence and intensity ofStrongyloidessp. No significant effect of sex on the prevalence of infection could be detected. There was some indication that female reproductive status was related toTrichurisegg output. In contrast to a previous study, no significant correlations between parasite infection and social rank could be found. Troop membership constituted the predominant factor contributing to heterogeneity of prevalence of infection. This suggests that spatial location and/or genetics may be important in determining levels of parasite infection.
Experimental study on the influence of paper and pulp mill effluent on the gill parasite communities of roach (Rutilus rutilus)
Authors: Bagge A. M. , Valtonen E. T. 
Published: June 2009

SUMMARYRoach (n= 81) caught on 23 May, 1992 from oligotrophic, unpolluted Lake Peurunka were kept in cages over a 2-week period before moving half of the fish to nearby Lake Vatia, which is influenced by pulp mill effluents. Before moving the fish gill parasites were examined from 9 fish; 5Dactylogyrusspecies,Gyrodactylussp. andParadiplozoon homoionwere found, the main components of the infracommunities being dactylogyrids. Afterwards, 5 fish from each lake were studied weekly between 1 July and 17 August. Metazoan parasites were recorded from gill arches divided into 4 sections along the dorso-ventral axis.D. crucifer, D. nanus, D. micracanthusandD. suecicusoccurred in both lakes throughout the study.Gyrodactylussp., Ergasilus briani andP. homoionoccurred in low numbers in both lakes. Differences between the lakes were seen in the prevalence ofD. micracanthuswhich was higher in Lake Vatia and significantly increased abundances ofD. crucifer, D. nanusandD. micracanthusin Lake Vatia. Abundances of otherDactylogyrusspecies remained, on average, at the same level in both lakes. No change during the experiment was recorded in the location of the two most common species,D. cruciferandD. nanus, on the host gills in either of the lakes, both species favouring the 2nd and 3rd gill arches and especially the inner parts of the gills. The apparent lack of competition between the 2 most commonDactylogyrusspecies indicates that no limitation of resources on roach gills occurred. This was also confirmed by the increased overlapping indices with increasing abundances between the two most common species in Lake Vatia.
Studies on ascaridoid nematodes in pythons: the life-history and development of Ophidascaris moreliae in Australian pythons
Authors: Sprent J. F. A. 
Published: June 2009

Several species of Australian python, Morelia spilotes variegatus, Liasis amethy-stinus, L. fuscus and L. childreni, were experimentally infected with eggs of Ophidascaris moreliae and the development of the larvae described. The first moult occurred in the egg, which survived and remained infective for over 7 years in moist conditions. The first moult occurred in 12 days and the second-stage larva in the egg was infective to mice in 14–21 days. After ingestion the larvae migrated to liver and lungs and in 21 days were mainly distributed throughout the subcutaneous tissues, particularly in the neck region and behind the ears. Growth occurred to about 8 mm; the larvae attained their infectivity for pythons after 5 weeks and retained it for more than a year. The second moult was not observed but it was assumed that the third stage was infective for pythons. Development to about the same length occurred in guinea-pigs and indigenous and laboratory rats and in the bandicoot (Isoodon obesulus). In the possum (Tricho-surus sp.) a more rapid growth occurred to about the same length. No growth occurred in tadpoles.After ingestion by pythons larvae migrated to the lungs, where they remained for 3 months or more, grew to a length of 45 mm and underwent the third moult. Larvae removed from the lungs and reingested by pythons returned to the lungs if they had been in the first python for less than 60 days. After this time, they remained in the stomach of the second python. During the third moult larvae underwent a marked constriction of the anterior end, moved up the trachea and became attached in the upper oesophagus as fourth-stage larvae. In mouse-infected M. spilotes the third moult occurred at 117 days at a length of 23–45 mm; fourth-stage larvae measured 34–50 mm. The fourth moult occurred in the stomach at 318 days at a length of 37–55 mm. The smallest adult specimens found were a 55 mm male and a 63 mm female. Development to the adult stage was only observed in M. spilotes variegatus. In other python species only pre-adult forms were recovered. It appeared that development may be retarded at the fourth moult during the winter. The morphology of the larvae during the five stages of development is described. It is concluded that the main growth phases are the third stage in the lungs of the python and the adult stage in the stomach of the python. Encapsulated forms were found only in the tissues of intermediate hosts. The larvae from mouse tissues emerged from the capsules during putrefaction and survived for several weeks in water.Acknowledgement is made to the able technical assistance of Miss Marian Hollis. Financial assistance for this study was provided under grants from the Australian Research Grants Committee and the United States Department of Health, Education and Welfare no. A 107023–02.
Monitoring the efficacy of different doses of praziquantel by quantification of circulating antigens in serum and urine of schistosomiasis patients
Authors: van Lieshout L. , de Jonge N. , El-Masry N. , Mansour M. M. , Bassily S. , Krijger F. W. , Deelder A. M. 
Published: June 2009

SummaryWe evaluated the quantitation of two schistosome circulating antigens in serum and urine as a tool for the assessment of the efficacy of praziquantel dosage regimens (40 versus 60 mg/kgbw). In addition we compared the efficacy of two different brands of praziquantel (Biltricide® and Distocide®), given at the same dosage (40 mg/kgbw). Thirty five Egyptian hospitalized schistosomiasis mansoni patients participated in this study. Thirteen patients (Group 1) received 60 mg/kgbw Biltricide®, administered in 3 oral doses of 20 mg in one day; 22 individuals (Group 2) were treated with 40 mg/kgbw (12 Biltricide®, 10 Distocide®), given in one oral dose. Circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) were quantitated by monoclonal antibody-based ELISA's before, and 1, 3 and 6 weeks after chemotherapy. Before treatment, all patients were positive for at least one of the circulating antigen assays. Three to six weeks after treatment significantly more patients were found to be negative in Group 1 compared to Group 2 (X2 = 7·13, P = 0·008, n = 35). Also the levels of CCA and CAA in serum and of CCA in urine were found to be significantly higher in Group 2 (Mann- Whitney U < 85, P < 0·05, n = 35). These results were confirmed by parasitological data. No differences were found between treatment with Biltricide® or Distocide®. Our results indicate that praziquantel treatment of schistosomiasis with 60 mg/kgbw divided in 3 doses results in a higher cure rate compared to 40 mg/kgbw as a single dose, and provide further evidence for the use of the CAA and CCA assays as a sensitive method to monitor the efficacy of chemotherapy, particularly when circulating antigen assays are combined by parallel testing.
ELISAs based on recombinant antigens for sero-epidemiological studies onToxoplasma gondiiinfections in cats
Authors: Tenter A. M. , Vietmeyer C. , Johnson A. M. , Janitschke K. , Rommel M. , Lehmacher W. 
Published: June 2009

SUMMARYTwo recombinantToxoplasma gondiipolypeptides, H4 and H11, were tested as diagnostic antigens in enzyme-linked immunosorbent assays (ELISAs). The results obtained by ELISAs based on single H4 (H4-ELISA), on single H11 (H11-ELISA) and on a mixture of H4 and H11 (H4/H11-ELISA) were compared with results obtained by an ELISA based on traditional ELISA antigen (TEA-ELISA), an indirect fluorescent antibody test (IFAT), the Sabin-Feldman dye test (SFDT) and a direct agglutination test (DAT). A total of 306 cats from a suburban cat population were tested of which about 45% showed serological evidence ofT. gondiiinfection. Infection rates varied from about 32% for cats kept indoors to about 55% for stray cats. Specificities > 99% were observed for all ELISAs based on the recombinant antigens (H4-ELISA, H11-ELISA and H4/H11-ELISA). The H4/H11-ELISA also reached a sensitivity of 95% which compared very favourably with those observed for the TEA-ELISA (98%) and for the IFAT (94%). Negative and positive predictive values for the H4/H11-ELISA were 96 and < 99%, respectively. Antibody titres measured by the H4/H11-ELISA also correlated well with those measured by the SFDT and the DAT. Hence, the H4/H11-ELISA appears to be a very suitable test for sero-epidemiological studies onT. gondiiinfections in cats.
Effects of culture and praziquantel on membrane fluidity parameters of adultSchistosoma mansoni
Authors: Lima S. F. , Vieira L. Q. , Harder A. , Kusel J. R. 
Published: June 2009

SUMMARYMembrane fluidity parameters, lateral diffusion coefficient and mobile fraction were assessed in male and femaleSchistosoma mansoniteguments immediately after their recovery from infected mice or after 24 or 48 h of culture. Our results show that male and female teguments have different properties and behave differently when in culture. In general, male worms displayed a tendency to increase their lateral diffusion coefficient while females showed a significant reduction. The effects of praziquantel (−) and praziquantel (+) on the fluidity properties of the worm surface were also studied. It was demonstrated that both enantiomers of the drug interact with the tegument inducing a decrease in the average velocity of lipid molecules. However, it is only the active form which reduces the number of molecules that are able to move. In explanation we propose that praziquantel (−) and praziquantel (+) have different ways of inserting into the tegument and that some of the effects of the drug are mediated by altering membrane fluidity.
Plagiorchis elegans: emergence, longevity and infectivity of cercariae, and host behavioural modifications during cercarial emergence
Authors: Lowenberger C. A. , Rau M. E. 
Published: June 2009

SUMMARYWe investigated changes in the behaviour of Stagnicola elodes associated with the emergence of Plagiorchis elegans cercariae. Within 15 min of the reduction in light intensity, which triggered the onset of cercarial emergence, infected snails moved to the top of the water column and remained there for 2–3 h. Seventy-nine percent of all cercariae that emerged from the snail did so during this period. Uninfected snails showed no such behavioural changes following the change in light intensity. Cercariae were released in a dense cloud around the snail at the water surface and dispersed passively. Within 3–4 h more than 80% of all cercariae had settled in the bottom 5 cm of the water column. The infectivity of cercariae increased from less than 20% upon emergence from the snail to greater than 75% 4–6 h post-emergence, and then declined steadily to below 5% by 24 h post-emergence. Cercarial longevity was greater than 30 h and exceeded the period of infectivity. This may be related to steadily falling endogenous glycogen levels. A delay in attaining maximum infectivity may represent an adaptive mechanism allowing time for cercarial dissemination, thus reducing superinfection, and subsequent parasite-associated mortality, of second intermediate hosts.
On the permeability of cestodes to colloids: an evaluation of the transmembranosis hypothesis
Authors: Lumsden Richard D. , Threadgold Lawrence T. , Oaks John A. , Arme C. 
Published: June 2009

SUMMARYAdult Hymenolepis diminuta were tested for their ability to transport colloids under in vitro and in vivo conditions. The tracers employed included colloidal thorium dioxide (Thorotrast), carbon (Pelikan Ink), ferritin and the 14C-labelled protein fraction from Chlorella vulgaris. Though certain of these tracers were adsorbed to the external surface of the tegument plasmalemma, no evidence for the assimilation of any of these colloids was obtained in the present study. Further, significant differences in size and structure between the granular inclusions reported earlier by Rothman (1967) as assimilated colloids and the particles present in the respective colloidal suspensions were noted. Results of this investigation are interpreted as rendering untenable previous conclusions concerning transmembranosis of colloids by tapeworms.
Fine structure of the nervous system and specialized nerve endings in the miracidium of Fasciola hepatica
Authors: Wilson R. A. 
Published: June 2009

SUMMARYThe fine structure and organization of the nervous system of the miracidium is described. The central ganglion consists of a mass of nerve fibres with peripherally situated cell bodies. Tracts of fibres run outward from the central mass to the muscles of the body wall and to specialized endings. The individual fibres contain several types of inclusions and synapses are common in the neuropile.Excluding the eyespots, four kinds of specialized nerve endings are described. Two of these types terminate at the body surface and bear ‘cilia’. The other two terminate internally, one type within the body wall and the other type laterally, slightly anterior to the central ganglion. It is suggested that the function of three of the types of ending might be sensory, detecting chemical and mechanical stimuli, and the direction of gravity. The function of the fourth type of ending is problematical but might be secretory.I am most grateful to Dr A. Robards for use of electron microscope facilities and to Mrs J. Denison for technical assistance.
Density-dependent processes in the transmission of human onchocerciasis: intensity of microfilariae in the skin and their uptake by the simuliid host
Authors: Basáñez M. G. , Boussinesq M. , Prod'hon J. , Frontado H. , Villamizar N. J. , Medley G. F. , Anderson R. M. 
Published: June 2009

SUMMARYThe transmission success ofOnchocerca volvulusis thought to be influenced by a variety of regulatory or density-dependent processes that act at various points in the two-host life-cycle. This paper examines one component of the life-cycle, namely, the ingestion of microfilariae by the simuliid vector, to assess the relationship between intake of larvae and the density of parasites in the skin of the human host. Analysis is based on data from three areas in which onchocerciasis is endemic and includes published information as well as new data collected in field studies. The three areas are: Guatemala (Simulium ochraceum sl.), West and Central Africa (savanna members of theS. damnosumcomplex), and South Venezuela (S. guianense). The data record experimental studies of parasite uptake by flies captured in the field and fed to repletion on locally infected subjects who harboured varying intensities of dermal microfilarial infection. Regression analyses of log transformed counts of parasite burdens ingested by the flies plotted against log transformed counts of microfilariae per mg of skin revealed little evidence for saturation in parasite uptake by the flies as the intensity in the human host increased. There was a positive and highly significant rank correlation between both variables for the three blackfly species. In an alternative analysis a model was fitted to data on prevalence of flies with ingested microfilariae (mff) versus dermal mean intensities. The model assumed an overdispersed distribution of the number of mff/fly and a given functional relationship between intake and skin load. The results of both approaches were consistent. It is concluded that parasite ingestiossssn by the vector host is not strongly density dependent in the three geographical areas and ranges of dermal loads examined. It therefore appears that this transmission process is of reduced importance as a regulatory mechanism in the dynamics of parasite population growth.
Interactions between the acanthocephalansPomphorhynchus laevisandAcanthocephalus anguillaein rainbow trout: testing an exclusion hypothesis
Authors: Bates R. M. , Kennedy C. R. 
Published: June 2009

SUMMARYRainbow trout were infected simultaneously with cystacanths of the two acanthocephalan speciesPomphorhynchus laevisandAcanthocephalus anguillaein the laboratory. Infections consisted of varying proportions of the two species (from 0 to 100%) at low (20 cystacanths) and high (60 cystacanths) levels. Fish were sacrificed at 7, 56 and 112 days post-infection (p.i.) and the parasites recovered. At low-level infections there was a high degree of overlap in the range of intestine occupied by the two species (44·12 %) and no evidence for interspecific competition affecting either species. At high-level infections the establishment of both species was unaffected by the presence or number of individuals of the other species. The survivorship and the range of intestine occupied byA. anguillaewere found to be reduced in the presence ofP. laevis. The interaction was one-sided, asP. laevisremained unaffected byA. anguillae, and so indicated interference competition. The possibility that both intraspecific and interspecific competition are implicated in explaining the distribution of the two species in the British Isles is discussed.
Trypanosoma brucei brucei: differences in the nuclear chromatin of bloodstream forms and procyclic culture forms
Authors: Schlimme W. , Burri M. , Bender K. , Betschart B. , Hecker H. 
Published: June 2009

SummaryNucleosome filaments of two stages of the life-cycle ofTrypanosoma brucei brucei, namely bloodstream forms and procyclic culture forms, were investigated by electron microscopy. Chromatin of bloodstream forms showed a salt-dependent condensation. The level of condensation was higher than that shown by chromatin from procyclic culture forms, but 30 nm fibres as formed in rat liver chromatin preparations were not found. Analysis of histones provided new evidence for the existence of H1-like proteins, which comigrated in the region of the core histones in SDS–PAGE and in front of the core histones in Triton acid urea gels. Differences were found between the H1-like proteins of the two trypanosome stages as well as between the core histones in their amount, number of bands and banding pattern. It can be concluded thatT. b. bruceicontains a full set of histones, including H1-like proteins, and that the poor condensation of its chromatin is not due to the absence of H1, but most probably due to histone–DNA interaction being weak. It is obvious that structural and functional differences of the chromatin exist not only betweenT. b. bruceiand higher eukaryotes, but also between various stages of the life-cycle of the parasite. It is therefore not adequate to investigate the chromatin only of the procyclic culture forms as a model for all stages of the life-cycle ofT. b. brucei.
Biochemical and morphological pathology of the foot of the schistosome vector Biomphalaria glabrata infected with Schistosoma mansoni
Authors: Thompson S. N. , Lee R. W. K. , Mejia-Scales V. , El-Din M. Shams 
Published: June 2009

SummaryInfection by Schistosoma mansoni resulted in morphological and biochemical changes to the foot of its intermediate host, Biomphalaria glabrata. Migration through, and emergence of cercariae from, the foot was observed and evidenced by lesions on the ciliated foot surface. This was accompanied by a significant decrease in the velocity of movement by infected individuals. In vivo31P NMR spectral analyses demonstrated that the foot of infected snails had a lower phosphoarginine (PA)/adenosine 5' triphosphate (ATP) ratio than that of uninfected controls. Moreover, kinetic experiments, employing saturation transfer, demonstrated the pseudo-first-order rate constant for the arginine kinase-catalysed exchange reaction in the forward direction, that is, PA→ATP was decreased by infection. The reverse reaction was not observed by the NMR methods used. PA was depleted upon exposure to hypoxic conditions suggesting its traditional role in preserving ATP level. Partly oxidized metabolic end-products were not observed in snails maintained under aerobic conditions, but succinate, propionate, acetate and lactate rapidly accumulated under hypoxic conditions.
The methionine synthesis cycle and salvage of methyltetrahydrofolate from host red cells in the malaria parasite (Plasmodium falciparum)
Authors: Asawamahasakda W. , Yuthavong Y. 
Published: June 2009

SummaryPlasmodium falciparum, P. knowlesi and P. chabaudi showed a significant activity of methylenetetrahydrofolate reductase (MTHFR). The presence of this enzyme completes the methionine synthesis cycle, in which the one-carbon fragment from serine side-chain can be transferred to methionine. However, while metabolic labelling of methionine from l-3 [14C]serine could not be demonstrated in P. falciparum, the significance of MTHFR was implicated by a novel pathway for salvage of exogenous 5-methyltetrahydrofolate from the host cell. The methyl group of the cofactor was incorporated into methionine, and the folate cofactor was found in the same pool as that derived from de novo synthesis with paminobenzoic acid as the precursor, shown previously as polyglutamylated 5-methyltetrahydrofolate. It is proposed from these results that the function of MTHFR and the methionine synthesis cycle is not the supply of methionine, but the generation of active folate cofactors from more stable precursors salvaged by the parasites