bluuebunny/crossref_metadata_2025_split huggingface dataset:
An analysis of the proteinases ofTrichomonas vaginalisby polyacrylamide gel electrophoresis
Authors: Coombs G. H. , North M. J. 
Published: June 2009

SUMMARYThe proteinases ofTrichomonas vaginalishave been analysed by electrophoresis in polyacrylamide gels containing denatured haemoglobin. Seven bands of activity were detected indicating multiple proteinases. All of the enzymes were stimulated by 1 mM dithiothreitol and had inhibitor sensitivities characteristic of cysteine proteinases. The enzymes differed significantly, however, with respect to pH optima and relative sensitivities to inhibitors.
The epidemiology of Ascaris lumbricoides and other soil-transmitted helminths in primary school children from Ile-Ife, Nigeria
Authors: Holland Celia V. , Asaolu S. O. , Crompton D. W. T. , Stoddart R. C. , Macdonald R. , Torimiro S. E. A. 
Published: June 2009

SummaryAn epidemiological survey of intestinal helminthiases was conducted on 766 primary school children aged 5–16 years from Ile-Ife, Nigeria. On the basis of stool examinations, the prevalence of Ascaris lumbricoides, Trichuris trichiura, hookworm and Strongyloides stercoralis was 88·5, 84·5, 33·1 and 3% respectively. Intensity of infection was measured indirectly by egg counts for each species of helminth and also by counting worms passed after chemotherapy in the case of A. lumbricoides. The influence of host age and sex on infection levels was assessed. Relationships between the intensities of A. lumbricoides, T. trichiura and hookworm in individual children were identified. After anthelmintic treatment with levamisole, the frequency distribution of A. lumbricoides per host and the relationship between parasite fecundity and worm burden were investigated.
Effects of infection with Echinostoma paraensei on the circulating haemocyte population of the host snail Biomphalaria glabrata
Authors: Noda S. , Loker E. S. 
Published: June 2009

SummaryCirculating haemocytes from Echinostoma paraensei-infected M line Biomphalaria glabrata snails, or from age- and sizematched control snails, were studied on plastic slides with phase-contrast optics. Granulocytes, hyalinocytes, and round cells were consistently present; granulocytes were further categorized as ‘fully spread' (FS) or ‘partially spread' (PS). Among control snails, the relative percentage and estimated number/mm3 of round cells declined significantly with increased snail size, and the corresponding values for both categories of granulocytes increased. At 1 day post-infection (p.i.) with E. paraensei, overall composition of the haemocyte population was relatively unaffected, but by 8 days p.i. infected snails had significantly higher relative percentages of round cells and PS granulocytes than controls. Because a marked increase in the number of circulating haemocytes is also evident by 8 days p.i., infected snails had approximately 12 times more round cells and PS granulocytes/mm3 of haemolymph than did controls. At 30 days p.i. the relative and absolute abundance of PS granulocytes was still significantly elevated, but otherwise haemocyte populations did not differ from control snails. Alterations in granulocyte size in infected snails were also noted. Infection with E. paraensei has a striking impact of circulating haemocyte populations and also increases the relative concentration of haemocytes with less ability to adhere to a foreign surface.
Factors affecting the adhesion of micro-organisms to the surfaces of plant-parasitic nematodes
Authors: Bird A. F. , Bonig Ingrid , Bacic A. 
Published: June 2009

SummaryThe influence of various agents on the adhesion of endospores of Pasteuria penetrans to the nematode Meloidogyne javanica was studied. Similarly, but to a lesser degree, we have also studied the adhesion of conidia of the fungus Dilophospora alopecuri and the coryneform bacterium Clavibacter sp. (syn. Corynebacterium rathayi) to the nematode Anguina agrostis (syn. A. funesta). Reduction in the degree of both spore and conidial attachment following their pre-treatment with periodate and the presence of PAS staining material on spores, conidia and bacteria implicated carbohydrate in these interactions. Tests involving both unbound and FITC-bound lectins demonstrated that wheat germ agglutinin (WGA) can inhibit the degree of attachment of P. penetrans to M. javanica and that this inhibition can be overcome by pre-treatment of the lectin with N, N′-diacetyl chitobiose. Endospores of P. penetrans, amphid and buccal secretions of 2nd-stage larvae of M. javanica and the cuticle and excretory pore secretions of 2nd-stage dauer larvae of A. agrostis bound WGA, indicating that accessible N-acetyl-D-glucosamine residues are present on these structures. Endospores of P. penetrans also bound Con A, indicating the presence of accessible α-D-glucose/α-D-mannose residues on their surface.
Schistosoma mansoni:morphology and ultrastructure of adult worms recovered from cyclosporin A-treated mice
Authors: Munro G. H. , McLaren D. J. 
Published: June 2009

SummaryCyclosporin A administered toSchistosoma mansoni-infected mice at around day 20 of infection reduces the worm burden by > 60%, as assessed by portal perfusion on days 28 and 86. Those worms recovered at perfusion have been examined by light and electron microscopy for drug-induced changes in morphology. Gross parasite damage was characterized by massive bolus formation and subsequent herniation of the gut. This event was attributed to the abnormal accumulation of crystalline structures in the lumen; the crystals were closely associated with lipid droplets, and were shown by X-ray micro-analysis to contain iron. Such crystals were seen only rarely in the intestines of control worms, but they too gave small iron peaks when examined by X-ray micro-analysis. In some drug-treated worms the caecal epithelium had ruptured, thereby releasing luminal contents throughout the worm body. In addition, herniations of the gut were seen protruding through the tegument causing surface deformation and disruption of tegumental and parenchymal tissues. The structural integrity of the worm was ultimately compromised allowing access to cytotoxic effector cells of the host. The combined effects of drug action and cellular cytotoxicity presumably account for the very significant levels of worm killing achieved by CsA treatment of the host.
Parasite-specific antibody reponses of responses of ruminants infected withTrypanosoma vivax
Authors: Vos G. J. , Gardiner P. R. 
Published: June 2009

SummarySera from goats and cattle that were infected with twoTrypanosoma vivaxclones (ILDat 1.2 and ILDat 2.1) derived from different stocks were analysed for antibody activity against the variable surface glycoproteins (VSGs) of the infecting clones by enzyme-linked immune assays (ELISA) and immune lysis. To obtain purified VSG, lysed trypanosomes were separated on dodecyl sulphate-polyacrylamide gels. The gels were copper stained and the VSG protein band was excised from the gel. After destaining, the proteins were electroeluted from the gel slices and used as antigens in ELISA. High titres of IgM and IgG1antibodies and lytic antibodies against the VSG of the infecting clone were detected. The IgG1response appeared about 4 days later than the IgM response. IgG2antibodies were only detected in goats and cattle that were infected with ILDat 1.2. Two goats and two calves that were infected with ILDat 1.2 showed recurrent peaks in lytic activity and of IgM and IgG1antibody activity to the VSG of the infecting variable antigenic type (VAT). Two goats that were infected with ILDat 2.1 showed a similar pattern, but in two other goats there was a recurrent peak only in the IgM class. Recurrent peaks of antibody activity to the VSG of ILDat 1.2 and ILDat 2.1 were not detected in the sera of goats that had been inoculated with irradiated trypanosomes or that had been infected with an unrelatedT. vivaxclone. The recurrence of antibody peaks against the VSG of infecting VATs suggests that trypanosomes with completely or partially identical surface determinants reappear duringT. vivaxinfection of ruminants.
The effect of Babesia microti on feeding and survival in its tick vector, Ixodes trianguliceps
Authors: Randolph S. E. 
Published: June 2009

SUMMARYEvidence is presented that Babesia microti may promote its transmission amongst rodents by enhancing the feeding success and survival of its tick vector, Ixodes trianguliceps. Both the mean engorged weight of larval ticks and the percentage moult of larvae to nymphs increased as larvae fed on naive hosts later in the parasitaemic cycle up to a point a few days beyond the loss of a patent infection. This increased feeding success and survival was not dependent on the level of infection by B. microti. Two possible, host-mediated mechanisms for the observed parasite–vector interactions are suggested, the anti-haemostatic effects induced by babesiosis and the interaction of the immunosuppressive effects of Babesia and the development of immunity to ixodid ticks by their vertebrate hosts.
A new species of Leishmania isolated from the great gerbil Rhombomys opimus
Authors: Strelkova M. V. , Shurkhal A. V. , Kellina O. I. , Eliseev L. N. , Evans D. A. , Peters W. , Chapman C. J. , Leblancq S. M. , Van Eys G. J. J. M. 
Published: June 2009

SUMMARYLeishmania turanica n.sp., found infecting the desert rodent Rhombomys opimus in the southern territories of the USSR and the Mongolian People's Republic, is described. This parasite exists sympatrically with L. major and L. gerbilli in R. opimus and is the predominant species. A total of 284 isolates of L. turanica from R. opimus, 3 from naturally infected Phlebotomus andrejevi and 1 from P. papatasi were characterized and found to be clearly distinguishable on isoenzyme and nuclear DNA characteristics from all other Old World taxa of Leishmania.
Relocation of Schistosoma mansoni in the lungs and resistance to reinfection in Rattus rattus
Authors: Imbert-Establet D. , Combes C. 
Published: June 2009

SUMMARYThe localization of adult Schistosoma mansoni originating from Guadeloupe (West Indies) was analysed in the natural host Rattus rattus in experimental and natural infections. A transfer of schistosomes from the porto-mesenteric system to the lungs occurs between the 4th and the 20th weeks post-infection, with a peak between 4 and 8 weeks; it should be noted that the worms start laying eggs at 4 weeks post-infection. In both experimentally and naturally infected R. rattus the relocation of schistosomes in the lungs is correlated with the total worm burden. Between 6 and 12 weeks post-infection some adult worms and numerous eggs are trapped in the liver. A high mortality in the worm population coincides with the migration of the parasites from the porto-mesenteric veins to the lungs. In re-infected R. rattus a relationship appears between the presence of schistosomes in the lungs and resistance to reinfection. It is concluded that, as already postulated previously in mice, resistance to re-infection in the natural host R. rattus is at least partly correlated with the hepatic pathology caused by the schistosomes of the primary infection.
DNA comparisons of Trypanosoma evansi (Indonesia) and Trypanosoma brucei spp.
Authors: Artama W. T. , Agey M. W. , Donelson J. E. 
Published: June 2009

SUMMARYTwo clones from separate isolates of Trypanosoma evansi in Indonesia were found by polymerase chain reaction (PCR) analyses to contain 3 different repeated nuclear DNA sequences of Trypanosoma brucei spp: the consensus sequence for a highly repetitive 177 base pairs and the gene repeats encoding procyclin and the spliced leader. In addition, the 994 bp minicircle sequence of one of the clones was determined, and PCR amplification primers specific for minicircles of T. evansi were identified that do not amplify minicircle sequences in the T. brucei spp. clones tested.
Development and survival of the free-living stages of Trichostrongylus tenuis, a caecal parasite of red grouse Lagopus lagopus scoticus
Authors: Shaw J. L. , Moss R. , Pike A. W. 
Published: June 2009

SUMMARYIn the laboratory, yields of infective 3rd-stage larvae of Trichostrongylus tenuis were determined by temperature when moisture was adequate. On the moor, eggs in caecal faeces did not develop to infective larvae during the winter. In summer, development did occur and yields of infective larvae were related to temperature: greatest yields were obtained when mean monthly soil surface temperatures ranged between 76 and 103°C. Rainfall was unimportant, as was desiccation. During summer the mean monthly mortality of infective larvae was 44% but over winter survival was negligible.
An extended proof of migration routes of immature parasites inside hosts: pathways of Nippostrongylus brasiliensis and Strongyloides ratti in the rat are mutually exclusive
Authors: Tindall N. R. , Wilson P. A. G. 
Published: June 2009

SUMMARYRigorous proofs applicable to the routes of migration of Strongyloides ratti and Nippostrongylus brasiliensis skin-penetrating juveniles inside the rat are extended. By applying the inequality principle (Tindall & Wilson, 1988) it was confirmed with a probability of error of I in 1010 that N. brasiliensis larvae applied to the skin passed through the lungs on their way to the intestine. Taking the analysis further, migrating larvae of S. ratti or N. brasiliensis were extracted from the nose or lungs, respectively, of donor rats and transferred to recipients by stomach tube to assay their ability to colonize the intestine. Results showed that (a) changes undergone by each parasite in its proven, specific transit site were essential before larvae could establish in the intestines of recipients, (b) these changes were not completed until larvae had been in the nose or lung for a significant period.
Cloning and characterization of ribosomal RNA genes from Opisthorchis viverrini
Authors: Korbsrisate S. , Mongkolsuk S. , Haynes J. R. , Wong Q. , Sirisinha S. 
Published: June 2009

SUMMARYThe ribosomal DNA (rDNA) unit of the liver fluke Opisthorchis viverrini has been cloned and characterized. The results demonstrated that the total length of this unit is approximately 13 kb, containing 4·2 kb of large subunit (LSU) rDNA, 2·0 kb of small subunit (SSU) rDNA, 1·0 kb of transcribed spacer DNA and 5·8 kb of non-transcribed + external transcribed spacer DNA. Examination of the non-transcribed spacer region between different rDNA units showed variation in the restriction sites rather than in the length. Judging from hybridization of the rDNA plasmid to the restriction endonuclease digest of genomic DNA, rDNA units represent 6·1% of the total genomic DNA. At the RNA level, the LSU rRNA of O. viverrini and Fasciola gigantica contained a hidden break. The molecule consisted of two fragments co-migrating with a SSU rRNA, when electrophoresis was carried out under denaturing conditions. Ribosomal RNA sequence comparison has been previously used to determine phylogenetic classification of parasitic organisms. The sequence of 381 nucleotides at the 5′ terminus of the LSU rRNA gene was determined and compared with those from species previously reported by other investigators. Phylogenetic classification of O. viverrini, as determined by rRNA gene sequence comparison, is comparable with the conventional taxonomic classification.
The effect of temperature on times to hatching of eggs of the nematode Ostertagia circumcincta
Authors: Young R. R. , Anderson N. , Overend D. , Tweedie R. L. , Malafant K. W. J. , Preston G. A. N. 
Published: June 2009

SUMMARYA delayed gamma distribution satisfactorily described the distribution of times to hatching of Ostertagia circumcincta eggs incubated in 0·1% saline at temperatures between 6 and 20 °C. Below 6 °C hatching of eggs was extremely variable. The relationship between rates of development and temperature within the range 10 to 20 °C was more closely described by a non-linear function than a linear one. The non-linear function was incorporated into a temperature summation equation which satisfactorily predicted the hatching of eggs incubated under conditions of alternating temperatures.
Studies on the life-cycle of Himasthla militaris(Trematoda: Echinostomatidae)
Authors: Vanoverschelde R. , Vaes F. 
Published: June 2009

SUMMARYIn this study two aspects of the biology of the cercaria of Himasthla militaris were examined. Firstly, the cercarial emergence from the first intermediate host, Hydrobia stagnorum, was studied. On a 9 h light (9L)/15 h dark (15D) schedule cercariae of Himasthla militaris emerged from naturally infected Hydrobia stagnorum predominantly during darkness. Inversion of the photo-period resulted in an immediate reversal of the emergence pattern. A comparison between the cercarial release patterns under natural conditions and in a constant light/temperature environment showed that an endogenous as well as an exogenous factor is controlling this process. Secondly, the penetration of the cercaria in Nereis diversicolor and the site-finding of the larva within this second intermediate host was investigated. After a short external migration on the body of N. diversicolor the cercaria enters the polychaete via the anus opening, perforates the gut-wall and moves through the coelom to the anterior segments to encyst in the muscle tissue. This internal migration results in a specific distribution pattern of the metacercariae, with more than 50% of the cysts localized in the first 12 segments and a maximum in segment number 9 (13·8%).
In vivoregulation ofS. japonicagranuloma formation by an IL-2 antagonist
Authors: Kresina T. F. 
Published: June 2009

SUMMARYThe present study shows anin vivorole for interleukin-2 in the formation of hepatic granulomatous inflammation in murineSchistosoma japonicuminfection. Mice which had been administered an inhibitor to interleukin-2 function during acute infection were noted to have reduced cell-mediated immune responses to ConA andS. japonicumsoluble egg antigen (SEA). Lymphoid tissue from these treated mice also have reduced numbers of cells which could be activated by ConA to produce interleukin-2 mRNA as shown byin situhybridization studies. Mice with less activated lymphocytes had, on the average, a 70% reduction in the granulomatous inflammation surrounding eggs deposited in hepatic tissues of acutely infected mice. The data demonstrate that IL-2 is a key factor in the generation of granulomatous inflammation inS. japonicuminfection and suggest that a potential anti-pathology vaccine could be generated based on limiting the presence of IL-2 generated during acute infection.
Studies on muscle cells isolated from Schistosoma mansoni: a Ca2+-dependent K+ channel
Authors: Blair K. L. , Day T. A. , Lewis M. C. , Bennett J. L. , Pax R. A. 
Published: June 2009

SUMMARYMuscle cells from adult male Schistosoma mansoni have been isolated using a combination of papain digestions and mechanical dissociation procedures. The muscle fibres isolated in this way lacked nuclei but they did contract and relax in response to high [K+], a response which was blocked in the presence of Co2+. From this we conclude that the isolation procedure yields viable muscle fibres useful for physiological studies. Patch-clamp recordings taken from the isolated fibres show a variety of discrete ionic conductances. In inside-out patches one prominent channel was a Ca2+-activated K+ channel with a conductance of 195 pS and a selectivity greater than 10:1 for K+ over Na+, Cs+ or NH4+. Percentage open time was dependent on [Ca2+] at the intracellular face. With [Ca2+] at 1 μM or greater percentage open time was > 95%; at 0.1 μM it was < 2%. No voltage sensitivity could be detected in the voltage range from –50 to –10 mV membrane potential. Ba2+ (10 mM), but neither tetraethylammonium nor 3,4-diaminopyridine blocked the channel from the intracellular face. This Ca2+-activated K+ channel in the muscle membrane of this acoelomate animal is similar in most respects to the maxi-K+ channels which have been described in a variety of cells from more highly evolved animals.
Relationship between faecal egg count and worm burden of Opisthorchis viverrini in human autopsy cases
Authors: Sithithaworn P. , Tesana S. , Pipitgool V. , Kaewkes S. , Pairojkul C. , Sripa B. , Paupairoj A. , Thaiklar K. 
Published: June 2009

SUMMARYThe relationship between faecal examination for egg output and worm burden of Opisthorchis viverrini in man of 181 autopsy cases from Northeast Thailand is described. Diagnosis of the parasite infection by stool examination for the presence of eggs was less sensitive than the worm recovery technique. Using Stoll's dilution and formalin–ether technique, no eggs were detected in the faeces of 20 cases harbouring low worm burdens (< 20 worms). The quantitative faecal egg count by Stoll's dilution technique showed a strikingly close positive correlation with the number of worms recovered (r = 0·96, P < 0·001) indicating a strong linear association between eggs per gram of faeces (epg) and worm burden. The number of epg per worm was inversely correlated to the worm burden (P < 0·001), suggesting that density-dependent constraints on fecundity could operate to restrict egg output in heavy infections. The accuracy of egg counts for estimating worm burden and its relevance to parasite epidemiological research are discussed.
Electrophoretic studies on enzymes of diploid and triploid paragonimus westermani
Authors: Agatsuma Takeshi , Habe Shigehisa 
Published: June 2009

SUMMARYAn enzyme analysis of diploid and triploid Paragonimus westermani was conducted using starch gel electrophoresis. In total, 16 enzymes, probably encoded by 18 loci, were studied for 3 populations of the diploid form sampled from 2 localities, and 4 populations of the triploid form from 4 localities. Comparison of the enzymes of the triploid and the diploid digeneans showed 5 different patterns; diaphorase (EC 1.6.2.2), glutamic-oxaloacetic transaminase (EC 2.6.1.1), hexokinase (EC 2.7.1.1), leucylglycylglycine aminopeptidase (EC 3.4.1.3), and phosphoglucomutase (EC 2.7.5.1). On the basis of the numbers of bands and their patterns, all individuals of the triploid are probably heterozygous at each of these 5 loci and homozygous at the remaining 13 loci. The occurrence of fixed heterozygotes found in triploid populations cannot be easily explained by only a single mutation. It is suggested that the variability may have been introduced by hybridization with a different sub-species or a closely related species and may, thus, have been maintained since the time of the origin of triploids.