bluuebunny/crossref_metadata_2025_split huggingface dataset:
Availability of caecal habitat as a density-dependent limit on survivorship ofLeptorhynchoides thecatusin green sunfish,Lepomis cyanellus
Authors: Ewald Julie A. , Nickol B. B. 
Published: June 2009

SUMMARYDistribution ofLeptorhynchoides thecatus(Acanthocephala: Rhadinorhynchidae) among the pyloric caeca and the relationship between site and rate of maturation were studied in laboratory infectons of 10, 25 and 40 cystacanths fed to green sunfish,Lepomis cyanellus. After 1 week fish fed at each intensity had significantly different numbers of worms. By the 3rd week post-infection, parasites disappeared from the anterior portion of the intestine. At this time the mean numbers of worms recovered from 25 and 40-cystacanth infections were not significantly different. At the end of the 1st week, the area where caeca join the alimentary tract (between caecal area) and caeca numbered 6 and 7 contained significantly more worms than the other sites. By the 3rd week post-infection only caecum 7 contained significantly more worms, and at 5 weeks there was no significant difference between the number of worms present in any caecum or the between caecal area. Initially worms in the more intense infections matured more slowly, but by the 3rd week post-infection there was no significant difference in the states of maturity. The rate of maturation was not related to the site occupied.
Ingestion of host blood by the monogenean Pseudodiplorchis americanus: a quantitative analysis
Authors: Tocque K. , Tinsley R. C. 
Published: June 2009

SUMMARYPseudodiplorchis americanus infects the urinary bladder of a desert toad and feeds exclusively on blood, producing the iron-rich waste product haematin. The host, Scaphiopus couchii, retains dilute urine within the urinary bladder as a water store throughout hibernation and parasite waste will therefore not be eliminated. This study utilized atomic absorption spectrophotometry to quantify the iron within the urinary bladders of infected and uninfected toads after different periods of hibernation. During the first 4 months hibernation, no detectable iron, above that of the controls, was found in the urine and bladder tissue of infected animals, but after 5–6 months hibernation there was a small but not significant increase. The iron contained within most individual parasites was greater than that detected in the urine and bladder tissue of the host, and the total iron in each parasite infrapopulation was 3–83 times greater than the urinary bladder iron. This suggests that the parasites do not regurgitate their gut contents during host hibernation. The amount of iron in individual parasites increased with time after migration to the bladder and this was used to estimate the amount of blood ingested by P. americanus. At a controlled temperature of 25 °C, the estimated rate of ingestion increased from 0·33 μl blood/parasite/week by worms 2 weeks post-migration to a maximum of around 1·6 μl by worms 5 months post-migration. The rate of blood ingestion by older worms was also calculated as a function of the hibernation period (since this did not correspond to worm age) assuming complete gut evacuation at the start of hibernation. This provided maximum estimates of ingestion rate of 1·9–5·3 μl blood/parasite/week.
In vitro release of the anti-gonadotropic hormone, schistosomin, from the central nervous system of Lymnaea stagnalis is induced with a methanolic extract of cercariae of Trichobilharzia ocellata
Authors: Schallig H. D. F. H. , Sassen M. J. M. , De Jong-Brink M. 
Published: June 2009

SUMMARYInfection with digenetic trematodes causes an inhibition or complete cessation of fecundity in their intermediate hosts, freshwater snails. It has been demonstrated in the host–parasite combination Lymnaea stagnalis–Trichobilharzia ocellata that the action of the female gonadotropic hormones upon their target organs is inhibited by the peptide schistosomin. Schistosomin is produced in the central nervous system of the snail and released upon parasitic infection. In order to study the in vitro release of schistosomin, a bioassay was developed. Central nervous systems were incubated with either an acetic acid or a methanolic extract of larval stages of Trichobilharzia ocellata (miracidia, mother sporocysts, cercariae). The incubation media were chromatographed using HPLC and released schistosomin (-like material) was tested for bioactivity in the calfluxin bioassay. The in vitro release of schistosomin was only induced with a methanolic extract of cercariae. The nature of the cercarial factor is discussed.
Immunosuppression by larvae ofMoniliformis moniliformis(Acanthocephala) in their cockroach host (Periplaneta Americana)
Authors: Lackie Ann M. , Holt Rohan 
Published: June 2009

SUMMARYThe results of 4 different assays for haemocytic immune responsiveness in the cockroach,Periplaneta americana, have shown that the presence of larvae ofMoniliformis moniliformiswithin the haemocoele depresses the insect's immune reactivity. Thus, the proportion of haemocytes that phagocytose fluorescent latex beadsin vivo, the proportion of haemocytes that can be stimulatedin vitroby theβ1,3-glucan, laminarin, to produce phenoloxidase, and the number of haemocytic aggregates producedin vivoin response to zymosan stimulation, are significantly depressed compared with control, unparasitized cockroaches. Also, when cockroaches are injected intra-haemocoelically with hatched oncospheres of the tapeworm,Hymenolepis diminuta, a higher prevalence and intensity of tapeworm larvae are found in insects already parasitized byM. moniliformis. All of these assays show that depression rather than total suppression of the immune response occurs; in the wild, this may be sufficient to ensure that the cockroach does not succumb to unrelated infections during the long developmental period of the parasite.
Comparative study on Rickettsia-like organisms in the midgut epithelial cells of differentGlossinaspecies
Authors: Shaw M. K. , Moloo S. K. 
Published: June 2009

SUMMARYThe midgut epithelium ofGlossina morsitans centralis, G. austeni, G. pallidipes, G. palpalis palpalis, G. p. gambiensis, G. fuscipes fuscipes, G. tachinoidesandG. brevipalpisfrom ILRAD-bred colonies was examined, by electron microscopy, for the presence and distribution of Rickettsia-like organisms (RLOs). RLOs were present in the midgut epithelial cells of all non-teneral tsetse. InG. m. centralis, G. pallidipesand, to a much lesser extent,G. brevipalpis, RLOs were numerous and were present in all the specimens examined. RLOs were present in fewer numbers in the epithelial cells of tenerals of these three tsetse species. In contrast, RLOs occurred in very much lower numbers within the midgut cells of nonteneralG. austeni, G. p. palpalis, G. p. gambiensis, G. f. fuscipesandG. tachinoides; were not seen in every specimen, and were rarely observed in the midgut cells of teneral tsetse. The RLOs were typical rod-shaped bacteria with an inner and outer membrane, which occurred free within the host cell cytoplasm and appeared to cause no obvious pathology. The micro-organisms divided by binary fission and at least two distinct morphological forms plus a range of intermediate forms were seen in the midgut cells. A comparison of the presence and numbers of RLOs within the midgut cells and the midgut infection rates of bothTrypanosoma congolenseandT. b. brucei, both betweenGlossinaspecies and also within the same stock of tsetse, clearly indicates that the ability of trypanosomes to establish and develop to mature infections is unlikely to be correlated solely with the presence of RLOs within the tsetse midgut.
Neuropeptide F: a novel parasitic flatworm regulatory peptide from Moniezia expansa (Cestoda: Cyclophyllidea)
Authors: Maule A. G. , Shaw C. , Halton D. W. , Thim L. , Johnston C. F. , Fairweather I. , Buchanan K. D. 
Published: June 2009

SUMMARYUsing a C-terminally directed pancreatic polypeptide (PP) antiserum and immunocytochemical methods, PP-immuno-reactivity (IR) was localized throughout the central (CNS) and peripheral nervous systems (PNS) of the cestode, Moniezia expansa. In the CNS, immunostaining was evident in the paired cerebral ganglia (primitive brain), connecting commissure, and the paired longitudinal nerve cords that are cross-linked by numerous regular transverse connectives. The PNS was seen to consist of a fine anastomosing nerve-net of immunoreactive fibres, many of which were closely associated with reproductive structures. Radioimmunoassay of this peptide IR in acid-alcohol extracts of the worm measured 192·8 ng/g of PP–IR. HPLC analyses of the M. expansa PP–IR identified a single molecular form which was purified to homogeneity. Plasma desorption mass spectrometry (PDMS) of purified parasite peptide resolved a single peptide with a molecular mass of 4599±10 Da. Automated gas-phase Edman degradation identified a 39-amino acid peptide with a C-terminal phenyl-alaninamide. Examination of its primary structure shows that it displays significant sequence homology with the vertebrate neuropeptide Y superfamily, suggesting that this platyhelminth-derived peptide is the phylogenetic precursor. Neuropeptide F (M. expansa) is the first regulatory peptide to be fully sequenced from the phylum Platyhelminthes and may represent a member of an important new class of invertebrate neuropeptide.
Schistosoma mansoni: male stimulation and DNA synthesis by the female
Authors: Hollander J. E. Den , Erasmus D. A. 
Published: June 2009

SUMMARYUnisexual females, (80–100 days post-infection) were cultured in vitro and exposed to mature male worms from either mixed or single-sex infections. A comparison was made of the uptake of [3H]thymidine (used as a marker for DNA synthesis) by isolated unisexual females or by those females exposed to males derived from either mixed or unisexual infections during in vitro culture. All males were observed to be paired with females by approximately 18 h post-culture. At 24 h post-culture females paired with males from mixed infections had an elevated uptake of [3H]thymidine compared to females that had not paired and uptake was also significantly different (P ≥ 0–001) from females exposed to males from unisexual infections. By 48 h there was no significant difference between uptake in females paired with either type of male. The frequency of uptake in the paired females was approximately double that in unstimulated females while non-paired females in the presence of males had an increase of between 35 nd 45%. In a second experiment the effect of depriving a mature egg-laying female of the paired male was investigated. These females had a continual decrease in uptake of [3H]thymidine compared to mature females maintained with male partners. The uptake of [3H]thymidine was used as a marker for DNA synthesis and the effect of the male worm on DNA synthesis in the unisexual female is discussed in view of the above results.
Experimental infection of chickens with two species of Eimeria isolated from the Malaysian jungle fowl
Authors: Long P. L. 
Published: June 2009

Two species of Eimeria isolated from jungle fowl of Malaysia were examined in infections of chickens. Eimeria diminuta reproduced well in the embryo CAM and caused severe infection of the lower small intestine and caeca of chickens, but did not develop in the duodenum. It reproduced well in chickens and severely affected their body weight gain. The endogenous stages and oocysts were similar to E. acervulina var. mivati and cross-protection tests with this parasite and E. acervulina confirmed the close relationship between them. It is suggested that the parasite should be referred to as E. acervulina var. diminuta.The oocysts of another species examined (E. indentata) were similar to E. maxima: the parasite reproduced well in chickens, was pathogenic and showed marked cross-protection against two strains of E. maxima isolated in Britain. The name E. maxima var. indentata is suggested for this parasite.When low immunizing doses of two strains of E. maxima isolated and maintained in Britain were given, they did not completely cross-protect against re-infection with the heterologous strain.
Independent expression of the metacyclic and bloodstream variable antigen repertoires ofTrypanosoma brucei rhodesiense
Authors: Turner C. M. R. , Barry J. D. , Vickerman K. 
Published: June 2009

SUMMARYThe variable antigen repertoire expressed by metacyclicTrypanosoma brucei rhodesienseis not influenced by the anamnestic expression whereby the variable antigen type (VAT) ingested by a tsetse fly is present at high levels in early bloodstream populations of fly-infected mice. This has been demonstrated by feeding toGlossina morsitansa trypanosome line expressing a VAT which is normally a component of the metacyclic repertoire. The VAT did not constitute a significantly increased proportion of the resultant metacyclic population which would have occurred had anamnestic expression and metacyclic expression been linked. Five other metacyclic VATs were also present at control levels. We conclude that the mechanisms of expression of VATs in the fly and in the mammal are independently controlled.
Finding and recognition of the snail intermediate hosts by 3 species of echinostome cercariae
Authors: Haas W. , Körner M. , Hutterer E. , Wegner M. , Haberl B. 
Published: June 2009

SUMMARYFinding and recognition of snail second intermediate hosts was studied in cercariae of 3 echinostome species. The cercariae of the 3 species accumulated in snail-conditioned water (SCW) with 2 types of orientation mechanisms and responded to different small molecular weight (< 500 Da) components of SCW. Pseudechinoparyphium echinatum and Echinostoma revolutum cercariae returned by swimming an arc, when swimming in decreasing concentration gradients of SCW (turnback swimming). The stimulating cues of SCW were identified as hydrophilic organic molecules, probably posessing amino groups. Amino acids contributed to the attractivity of SCW, at least in P. echinatum, but they could not account for the complete attractivity of SCW. Hypoderaeum conoideum were directed chemotactically and swam along increasing concentration gradients of small peptides within SCW, but in decreasing SCW gradients they showed no turn-back swimming. Chemotactic orientation in H. conoideum only started 1 h after emission, which may assist the cercariae to leave the immediate area of their first intermediate host snails and to disperse. Attachments occurred specifically to snail hosts in the 3 species and were stimulated by macromolecular mucus compounds, probably mainly by viscoelastic properties of the mucus. The results of this study show, that host-finding mechanisms and the stimulating host cues of snail invading echinostome cercariae differ considerably from those of schistosome miracidia.
Coccidia of the domestic goat Capra hircus, with notes on Eimeria ovinoidalis and E. bakuensis (syn. E. ovina) from the sheep Ovis aries
Authors: Norton C. C. 
Published: June 2009

SUMMARYEimerian oocysts were found in 98% of 422 faeces samples from goats in SE England. It was found that 74% of the samples contained thousands or tens of thousands of oocysts/g. Kids less than 1 year old had higher oocyst counts than yearling or adult goats. Nine species of Eimeria were identified, and 65% of the samples contained 3–5 species. The most prevalent species were E. arloingi (94%), E. hirci (69%), E. christenseni (64%) and E. caprina (55%). E. ninakohlyakimovae (48%), E. alijevi (42%) and E. apsheronica (23%) were common, and E. joichijevi (8%) and E. caprovina (4%) were comparatively rare. Developmental stages of E. caprina destroyed the crypt epithelium in the mucosa of the large intestine, causing severe haemorrhagic enteritis similar to that produced by E. ninakohlyakimovae. The literature on Eimeria species in sheep and goats is reviewed and, on the grounds of priority, E. bakuensis is the correct name for E. ovina in sheep.
Killing of schistosomula ofSchistosoma mansoniby macrophages: induction by T-cell clone-derived lymphokines and interferon-gamma
Authors: Kubelka C. F. , Ruppel A. , Krammer P. H. , Gemsa D. 
Published: June 2009

SUMMARYThe induction of schistosomulicidal activity of peritoneal macrophages by concanavalin A-stimulated supernatants from long-term T-cell clones and by interferon-gamma (IFN-γ) was investigated in detail. Optimal conditions ofin vitromacrophage activation by T-cell clone supernatants were established. Macrophages from 13-weekS. mansoni-infected mice responded to lymphokine activation as well as resident mnacrophages from uninfecteci mice. IFN-γ was shown to play an essential role in induction of schistosomulicidal macrophage activity: recombinant IFN-γ at high concentration could induce schistosomula killing, and an anti-IFN-γ antiserum inhibited the induction ofschistosomulicidal activity by T-cell clone supernatants. Our data also indicate that macrophage activation could be obtained by IFN-γ in synergy with other lymphokines in the supernatant of long-term T-cell clones. Macrophages from mice injected with T-cell clone supernatants were primedin vivoand triggered to kill schistosomula in vitro in the presence of lipopolysaccharide (LPS). The data demonstrate that lymphokines produced by T-cell clones and, in particular, IFN-γ can participate in the activation of schistosomulicidal macrophages.
The host-parasite relationships in pyridoxine (vitamin B6) deficient cotton rats infected with Litomosoides carinii (Nematoda: Filaroidea)
Authors: Beg M. A. , Fistein J. L. , Storey D. M. 
Published: June 2009

SUMMARYThis paper demonstrates that the establishment and growth of the filarial nematode parasite, Litomosoides carinii, is reduced in pyridoxine-deficient cotton rats. Young cotton rats were assigned to one of three dietary groups: vitamin B6-deficient cotton rats (B6 –AL) were fed a pyridoxine-free diet ad libitum; pair-fed controls (B6 + PF) were fed the same amount of pyridoxine-free diet as animals in the deficient group and given daily oral supplements of 100 μg pyridoxine; and pyridoxine-sufficient controls (B6 + AL) were fed the pyridoxine-free diet ad libitum and supplemented daily with 100 μg pyridoxine. Half of each group was infected with 50 L3 of L. carinii by subcutaneous injection 8 weeks after the start of the experimental feeding period. B6-deficient cotton rats ate less (P < 0·001) and gained less weight (P < 0·001) than B6-supplemented controls. The levels of microfilaraemia in deficient animals, measured weekly throughout the experiment by taking blood smears, was significantly lower than in supplemented animals (P < 0·001). The deficient rats became latent for L. carinii at 20 weeks post-infection, whereas there was patent microfilaraemia in rats in the other dietary groups until the end of the experiment. Smaller (P < 0·001) and fewer (P < 0·05) adult worms were recovered from the pleural and abdominal cavities of deficient animals than from either pair-fed or sufficient controls at autopsy 28 weeks post-infection.
Immunolocalization of aSchistosoma mansonifacilitated diffusion glucose transporter to the basal, but not the apical, membranes of the surface syncytium
Authors: Zhong C. , Skelly P. J. , Leaffer D. , Cohn R. G. , Caulfield J. P. , Shoemaker C. B. 
Published: June 2009

SUMMARYAdult parasites ofSchistosoma mansonireside within vertebrate mesenteric veins where they consume immense quantities of host glucose after transporting the sugar through their surface syncytium or tegument. Previously we obtained cDNA clones encoding two functional facilitated diffusion glucose transporter proteins expressed byS. mansoniadult worms (Skellyet al.1994). Antibodies specific for one transporter (SGTP1) have been generated against an extrafacial and an internal domain of the protein and used to localize the protein by light and electron microscopy. By light microscopy both antibodies stain a linear structure approximately 1–5 μm from the surface of the tegument of adult male and female schistosomes. Electron microscopic examination of frozen thin sections show binding of the antibodies to membranes in the base of the tegument and not to the membranes covering the outer surface or their invaginations. Analysis of the gold distribution suggests that the extrafacial domain is disposed toward the interstitial space beneath the tegument and the internal domain faces the syncytial plasm. The localization suggests that SGTP1 may function to transport free glucose from within the tegument and into the interstitial fluids that bathe the internal organs of these parasites.
Comparison of immune responses in inbred lines of chickens toEimeria maximaandEimeria tenella
Authors: Bumstead J. M. , Bumstead N. , Rothwell L. , Tomley F. M. 
Published: June 2009

SUMMARYImmune responses of 4 inbred lines of chickens, that differ in resistance toEimeria maximaandE. tenella, were examined. Significant differences were found inin vitroproliferation of peripheral blood lymphocytes toE. maximasporozoite antigen, the more resistant lines C and 72having higher responses than the more susceptible line 151. These differences existed pre-infection and were enhanced following both primary and a second infection. The proportions of lymphocyte subsets in the peripheral blood following primary infection also differed between lines, with significantly higher percentages of CD8 + and TCR1 + lymphocytes circulating in the more resistant birds. In contrast, there were few differences between lines in either resistance or inin vitroproliferation of peripheral blood lymphocytes toE. tenellasporozoite antigen either pre-infection or following a primary infection. However, after a second infection when there were significant differences in resistance between lines, as measured by oocyst excretion, there were also significant differences in lymphoproliferation with the more resistant lines 151 and 62having higher responses than the more susceptible line C. Thus forE. maximathere is a direct relationship between resistance to infection and lymphoproliferation in response to parasite antigen. This implies that differences in cellular immunity may account for differences in resistance between lines, and since these specific responses are enhanced by infection they may also reflect important immune mechanisms. For the rather less immunogenicE. tenella, the correlation between resistance and lymphoproliferation is not so clear. However, where there were significant differences between lines, i.e. after a second infection, the direct relationship between resistance and lymphoproliferation was upheld.
Comparative efficacy of diethylcarbamazine and mebendazole for the treatment of human toxocariasis
Authors: Magnaval J. F. 
Published: June 2009

SUMMARYAn open randomized study was carried out to assess the efficacy of diethylcarbamazine (DEC) and mebendazole (MBZ) across, respectively, 39 and 41 patients, all exhibiting clinical and biological features evocative of toxocariasis, together with a positive immunodiagnosis by Western blot usingToxocaralarvae excretory-secretory antigens. Clinical impact of the disease was quantified by a score system (20 parameters). Post-treatment follow-up used also results from eosinophil counts from total and specific anti-ToxocaraIgE quantitations, and from Western blots. All patients attended the control check-up 1 month after the end of treatment. Analysis of the results showed a similar good efficacy of DEC and MBZ on clinical score and eosinophil count that were significantly lowered. MBZ therapy was slightly more efficient on specific anti-ToxocaraIgE kinetics, while total IgE mean titres were not affected by either DEC or MBZ treatment. Patients from the DEC group reported a significantly higher rate of adverse reactions, most of which could be due to parasite lysis. This fact could be a strong argument for treating human toxocariasis with MBZ.