bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppression ofTaenia crassicepsduring concurrent infections withMesocestoides cortiin mice
Authors: Joysey H. S. 
Published: June 2009

SUMMARYParasite burden (by volume) was measured in female mice of three strains given single or concurrent infections ofMesocestoides cortiandTaenia crassiceps. Significant suppression ofT. crassicepsvolume was observed over a range ofM. cortiinocula and occurred irrespective of whetherM. cortiwas introduced before or after infection withT. crassiceps. Suppression ofT. crassicepsvolume was greatest with larger inocula ofM. cortiand with increased duration ofM. cortiinfection. No significant difference was found in the intraperitoneal volume ofM. cortifrom mice given single or simultaneous concurrent infections ofM. cortiandT. crassiceps. WhenM. cortiwere inoculated into mice with an established infection ofT. crassicepsa significantly smaller volume ofM. cortiwas retrieved at post-mortem from the peritoneal cavities of these mice, than from mice given justM. corti.
A model to assess survival mechanisms of parasites in a genetically defined host system
Authors: Arnason A. N. , Dick T. A. , Wassom D. L. 
Published: June 2009

SUMMARYWe examined a host system (Peromyscus maniculatus) in which a single autosomal gene controls susceptibility or resistance to infection by the cestode parasite Hymenolepis citelli. Parasite deaths of both primary and secondary (challenge) infections were examined, using a probabilistic model, to see if deaths were random and uncorrelated within each genotype. Within susceptible hosts, post-patent survival of primary worms was not random and heterogeneity was due to among-host effects rather than parasite-age effects, suggesting a second genetic or immunological process. Secondary infections in susceptible hosts appear to be lost randomly, independent of primary infection age or burden. The loss rate is similar to that for primary worms. The lack of correlation or alteration in (susceptible) host response to primary and secondary infections suggests that the latter are eliminated by a process that differs from that acting on primary worms. In resistant hosts, parasite survival rates suggest that the immunological process elicited by the primary infection also acts to eliminate the secondary infection more rapidly. Suggestions are made for improving experimental methods when dealing with mixed genotype populations. Experiments should permit direct estimation of genotype frequency and of parasite death rates within each genotype. This separation of host type is particularly important when studying correlation of successive worm burdens since any host or treatment mixture (genotype, age, sex, size or infection dose) may induce correlations that could be mistakenly interpreted.
Acquired resistance to Onchocerca lienalis infections in Simulium ornatum Meigen and Simulium lineatum Meigen following passive transfer of haemolymph from previously infected simuliids (Diptera, Simuliidae)
Authors: Ham P. J. 
Published: June 2009

SUMMARYThis study describes experiments which demonstrate the presence of a parasite-induced or derived factor in the haemocoel of Onchocerca lienalis-infected simuliids. Haemolymph, when transferred from previously infected donor flies to previously untreated recipient flies, using fine glass needles, confers protection against a subsequent challenge to the recipients. In three trials using Simulium ornatum sl. or S. linealum, significant levels of protection in ‘immunized’ compared to ‘challenge control’ groups were achieved (84% and 81% with S. ornatum sl. and 85% with S. lineaturm). This is despite the fact that the worm burdens of the infected donor groups in the three trials were very different (means of 33·1 and 3·4 larvae/fly with S. ornatum sl. and 1·6 larvae/fly with S. linealum). The use of sham-operated and bentonite-inoculated control groups demonstrate that this effect is not merely a non-specific reaction to trauma, but is probably parasitic in its derivation. The use of double infections separated by 4 days shows that the donor flies have themselves probably acquired resistance to O. lienalis. Frequency distributions of O. lienalis burdens in individual flies show that there is a shift froni a normal to a skew distribution when comparing ‘challenge control’ flies with ‘immunized’. This possible acquired resistance could have important implications in the transmission of forest and savanna human onchocerciasis by the Simulium damnosum complex.
Lamellar membranes associated with rhoptries in erythrocytic merozoites ofPlasmodium knowlesi: a clue to the mechanism of invasion
Authors: Bannister L. H. , Mitchell G. H. , Butcher G. A. , Dennis E. D. 
Published: June 2009

SUMMARYIn merozoites ofPlasmodium knowlesi, rhoptries have a dense substructure of fine (2·5 nm diameter) granules and short rods. These are not altered by lipid extraction, and stain with ethanolic phosphotungstate indicating a proteinaceous composition. Various types of fixation also show multilamellar whorls with a periodicity of 5–7 rim in the tips of rhoptries or extruded at the merozoite apex. In merozoites fixed during invasions of red cells, membrane continuity typically occurs between the rim of the rhoptry canal and the red cell membrane, but where this contact has apparently been lost, extensive membranous whorls and blebs are often found at the apex of the parasite. Similar structures occur at the spices of merozoites within late-stage schizonts. It is suggested that the same mechanism which generates these lamellae forms the parasitophorous vacuole by inserting membranous elements formed by the parasite into the red cell membrane, so causing its invagination. A similar mechanism may be responsible for the release of merozoites from the late-stage schizont.
The RFLP analysis of the β-tubulin gene region in New World Leishmania
Authors: Mendoza-León A. , Havercroft J. C. , Barker D. C. 
Published: June 2009

SUMMARYWe have examined the similarities and differences in the organization of tubulin genes in New World Leishmania by restriction endonuclease digestion of genomic DNA and Southern blot analysis, using heterologous and homologous tubulin gene probes. As judged by the hybridization pattern and the restriction fragment length polymorphism (RFLP), there were large differences in both the restriction and hybridization patterns of the β-tubulin sequences between stocks of the mexicana and braziliensis complexes. There were similarities in the hybridization patterns of different speciesof the mexicana complex. In contrast, a high heterogeneity was found between species of the braziliensis complex which includes intraspecific variation. The results suggest that this polymorphism may be associated with random mutations. The same analysis gave evidence of large differences in the β-tubulin gene restriction pattern between New and Old World Leishmania. This variation in the β-tubulin gene region was sufficient to distinguish between New and Old World Leishmania groups and between stocks of the mexicana and braziliensis complexes.
Differentiation of isolates in the genus Steinernema (Nematoda: Steinernematidae).by random amplified polymorphic DNA fragments and morphological characters
Authors: Liu J. , Berry R. E. 
Published: June 2009

SUMMARYWe combined polymerase chain reaction (PCR) amplification of DNA sequences and important morphological characters as a technique to differentiate nematode isolates in the genus Steinernema. Five decamer oligonucleotide primers were used to generate random amplified polymorphic DNA (RAPD) fragments from 11 nematode isolates. The primers generated 8–12 fragments, ranging from 220 to 1300 bp in size. Reproducible amplified DNA fragments of 11 isolates showed obviously inter- or intra-specific polymorphisms, enabling us to differentiate easily the nematode species and isolates. Combining RAPD–PCR fragments with the examination of morphological characters of infective juveniles and 1st-generation males, we identified isolate OH1S, collected from Newport, Oregon, as S.feltiae; isolate OS21, collected from Grants Pass, Oregon, belonged to a previously undescribed species. Our study may provide a rapid and reliable method for the identification of Steinernema nematodes.
Progarnia archosauriaenov. gen., nov. sp. (Haemosporina: Garniidae), a blood parasite ofCaiman crocodilus crocodilus(Archosauria: Crocodilia), and comments on the evolution of reptilian and avian haemosporines
Authors: Lainson R. 
Published: June 2009

SUMMARYProgarnia archosauriaenov. gen., nov. sp. (Haemosporina: Garniidae) is described in the blood of the South American caiman,Caiman crocodilus crocodilus(Archosauria: Crocodilia). The parasite undergoes merogony and gametogony principally in leucocytes and thrombocytes, but also invades erythrocytes in which it produces no ‘malarial’ pigment. It thus shares features ofFallisiaandGarniawhich are, respectively, intra-leucocytic and intra-erythrocytic haemosporines of the family Garniidae in present-day lizards. This, and the antiquity of the order Crocodilia, suggests that it was from such a parasite that the existing reptilian and avian haemosporines evolved. An overall evolutionary pattern is suggested.
Initiation of chemical studies on the immunoreactive glycolipids of adultAscaris suum
Authors: Dennis R. D. , Baumeister S. , Smuda C. , Lochnit C. , Waider T. , Geyer E. 
Published: June 2009

SUMMARYThere is a general lack of basic information concerning one class of glycoconjugate, the glycolipids, from parasitic nematodes. As the prototype, the neutral glycolipid fraction derived from adult males ofAscaris suumwas investigated as to its chromatographic, differential chemical staining, antigenic and chemical properties. The thin-layer chromato-graphy-resolved neutral fraction glycolipids could be classified into components of fast and slow migrating band groups. Immunoreactivity was restricted to the latter as detected by IgG and IgM anti-neutral fraction glycolipid antibody levels in serial infection sera of mice. Similarities of chromatography, antigenicity and serological cross-reactivity have been extended to the neutral glycolipid fractions of other parasitic nematodes:Litomosoides cariniiandNippostrongylus brasiliensis. Chemical, differential chemical staining and enzymatic analyses identified theAscaris suumantigenic, slow migrating band group of components as amphoteric glycosphingolipids, and not the originally hypothesized glyco-glycerolipids or glycosylphosphatidylinositols, that contained typical neutral monosaccharide constituents and a zwitter-ionic phosphodiester linkage, most probably phosphocholine. Glycosphingolipid-immunoreactivity is eliminated on cleavage of the zwitterionic phosphodiester linkage by hydrofluoric acid treatment.
Further studies of cyclical transmission and antigenic variation of the ILDar 1 serodeme ofTrypanosoma vivax
Authors: Gardiner P. R. , Thatthi R. , Gathuo H. , Nelson R. , Moloo S. K. 
Published: June 2009

SUMMARYAntigenic variation in the ILDar 1 serodeme of the naturally rodent-infective stock of West AfricanTrypanosoma vivaxhas been investigated following cyclical transmission. The immunofluorescent and immune lysis tests were employed with a panel of 39 variant-specific mouse antisera. When antigenically homogeneous, or mixed, populations were transmitted by tsetse flies to goats, the first peak parasitaemias arising in the goats were antigenic mixtures (up to 9 major, and several minor variants being recognized in some cases) from which the ingested variant was absent. Although first peak parasitaemias in similarly infected goats showed some variants in common, there was no obvious relationship between the VAT profiles in different goats. When these populations were expanded in irradiated mice, VAT heterogeneity was maintained with a tendency towards the development of predominant variants in some, but not all, instances. Six additional variants, derived following the growth of bloodstream form ILDat 1·9 in 37°C culture, were also represented in goat and mouse populations. Two further variants, isolated after cyclical development of ILDat 1·9-derived trypanosomesin vitro, were not present in the early parasitaemias in goats and mice.
A female-specific cDNA sequence ofSchistosoma mansoniencoding a mucin-like protein that is expressed in the epithelial cells of the reproductive duct
Authors: Menrath M. , Michel A. , Kunz W. 
Published: June 2009

SUMMARYSeven cDN A clones ofSchistosoma mansonicontaining the C-terminal part of the deduced sequence of a mucin-like protein have been identified. The protein contains 28% threonines, 20% serines, and has a pi of 3middot;4. On Northern blots of RNA of adult worms, the cDNA clones detect 2 transcripts of 1middot;65 and 4middot;2 kb which are expressed only in female worms. The tissue of gene expression, as revealed byin situhybridization, is the epithelium surrounding the female reproduction duct proximal to its entrance into the ootype. Accumulation of N-glycosylation sites suggests that the protein, like other mucins, might form a protective layer, coating the lining of the duct. Regarding its acidic pi, we hypothesize a role in preventing premature egg-shell formation. This is the first female-specifically transcribed sequence, hitherto known inS.mansonithat is not expressed in the vitellaria.
The FMRFamide-like neuropeptide AF2 is present in the parasitic nematode Haemonchus contortus
Authors: Keating C. D. , Holden-Dye L. , Thorndyke M. C. , Williams R. G. , Mallett A. , Walker R. J. 
Published: June 2009

SUMMARYPeptides belonging to the FMRFamide family are widely distributed amongst invertebrates. We report here on the isolation of the FMRFamide neuropeptide AF2 (Lys-His-Glu-Tyr-Leu-Arg-Phe-NH2) from the parasitic nematode Haemonchus contortus. Immunocytochemical techniques showed that FMRFamide-like material was distributed in several regions of these organisms including nerve cords and cell bodies of the central nervous system. AF2 was isolated using a method that employed 6 steps of reverse-phase HPLC. The concentration of AF2 in this organism was approximately 30 pmol/g of nematode.
Immunohistochemical and ultrastructural localization ofSchistosoma mansonisoluble egg antigens processed by the infected host
Authors: Bogers J. J. P. M. , Nibbeling H. A. M. , Deelder A. M. , Van Marck E. A. E. 
Published: June 2009

SUMMARYThe detection of egg-derived antigens in the serum and urine ofSchistosoma mansoni-infected individuals and experimental animals would provide an alternative method to assess the tissue egg burden. The detected levels are, however, not only a function of the amounts of antigen produced, but also of the processing or clearance by the host. In the present study the immunolocalization pattern of antigens using 2 recently described monoclonal antibodies to repetitive carbohydrate epitopes ofS. mansonisoluble egg antigen (114–5B1–A and 114–4D12–A) in various organs of the host was investigated. In the liver strong immunoreactivity could be detected around the entrapped eggs and in egg-shells, as well as in Kupffer cells accumulating both antigen and schistosomal pigment. In the spleen, immunohistochemistry revealed antigen in the plasma as well as in secondary lysosomes of macrophages. Strong labelling was found in the vesicles of the eosinophilic granulocytes: indirect evidence perhaps for the presence of antigen–antibody complexes. In conclusion, the secreted egg antigens were sequestered in the reticulo-endothelial macrophages of the liver and the spleen as already partly described for worm-derived antigens. The presence of large quantities of antigenic material in the spleen could suggest an important role of this organ in the clearance of antigen and might even provide an additional explanation for the hepatosplenomegaly mainly present inS. mansoni-infected children.
Measuring aggregation of parasites at different host population levels
Authors: Boulinier T. , Ives A. R. , Danchin E. 
Published: June 2009

SUMMARYParasites are generally found aggregated among hosts. In this paper we propose a method for measuring aggregation at different scales in the host population. We use the method to characterize the pattern of aggregation of the tickIxodes uriaeon chicks of its seabird host, the KittiwakeRissa tridactyla. We found evidence of aggregation at the among-nest scale, but not among chicks within nests. This shows that the processes leading to aggregation occur at a higher scale than the nest. The methods we develop provide a way to compare parasite aggregation at different scales in a quantitative fashion and can be applied in a large number of epidemiological studies.
Distribution and biophysical properties of fluorescent lipids on the surface of adultSchistosoma mansoni
Authors: Redman C. A. , Kusel J. R. 
Published: June 2009

SUMMARYThe properties of 4 fluorescent lipid compounds in the surface membrane of adult maleSchistosoma mansoniworms were examined by fluorescent microscopy and fluorescent recovery after photobleaching (FRAP). The data suggest that the probes N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl) sphingosine (BODIPY FL ceramide) and PKH2 pass through the outer membrane and enter structures in or below the membrane. In contrast 5-(N-octadecanoyl)aminofluorescein (AF18) and N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl) sphingosylphosphocholine (BODIPY FL sphingomyelin) insert into the outer monolayer. The DLvalues of these latter 2 compounds, 8·83 ± 2·35 × 10−9cm2s−1and 2·76 ± 0·53 × 10−9cm2s−1, respectively, suggest that they enter different domains. Furthermore, it was observed that both BODIPY FL ceramide and BODIPY FL sphingomyelin entered particular structures in or under the surface membrane. The possible nature of these particles is discussed.
Direct sequencing of the PCR amplified SSU rRNA gene ofEntamoeba disparand the design of primers for rapid differentiation fromEntamoeba histolytica
Authors: Novati S. , Sironi M. , Granata S. , Bruno A. , Gatti S. , Scaglia M. , Bandi C. 
Published: June 2009

SUMMARYSince 1993, strains ofEntamoeba histolytica sensn latohave been assigned to 2 species on the basis of clinical, biochemical, immunological and genetic evidence: the pathogenic strains toE. histolytica sensu stricto, the non-pathogenic strains toEntamoeba dispar. Analysis of the gene encoding for the small subunit ribosomal RNA (SSU rDNA) supports the existence of 2 species. However, while 3 whole SSU rDNA sequences are available in the data bases forE. histolytica, only a partial sequence has been published forE. dispar. Here we report a SSU rDNA sequence forE. dispar. Compared to those ofE. histolytica, this sequence shows 1·7 % nucleotide substitutions. On the basis of our rDNA data, 2 primers were designed to produce polymerase chain reaction (PCR) amplification from bothE. histolytica and E. dispar. Primer specificity for the 2 amoebae was assessed both theoretically against the data bases, and experimentally against a collection of eukaryotic and prokaryotic DNAs. The amplified stretch encompasses a polymorphicDdeI restriction site which allows, after cleavage of the fragment,E. histolyticaandE. disparto be distinguished. The reliability of this method of identification was assessed comparing the results with those based on classic isoenzyme analysis.
Karyotype variability in Trypanosoma rangeli
Authors: Henriksson J. , Solari A. , Rydåker M. , Sousa O. E. , Pettersson U. 
Published: June 2009

SUMMARYThe molecular karyotypes of several different protozoan parasites show high intra-species variation, including different kinetoplastids such as Trypanosoma brucei, Trypanosoma cruzi and Leishmania ssp. In this study, the molecular karyotype of Trypanosoma rangeli was examined. To evaluate potential intra-species molecular karyotype variations, 16 different samples were studied by pulsed field gel electrophoresis (PFGE) followed by ethidium bromide staining and hybridizations with 6 different probes. The result showed that different T. rangeli populations are highly polymorphic regarding the molecular karyotype, and thus suggests that PFGE analysis can be used for classification of different T. rangeli isolates. In addition, the molecular karyotype of T. rangeli was compared to molecular karyotypes of other kinetoplastids, and was shown to be distinctly different from that of T. cruzi, but shows some similarities with the karyotype described for T. brucei. Among the probes used one was identified as highly polymorphic, and thus informative for studies of different T. rangeli populations, and another was useful for differentiation between T. rangeli and T. cruzi.
Surface antigens ofToxoplasma gondii
Authors: Couvreur G. , Sadak A. , Fortier B. , Dubremetz J. F. 
Published: June 2009

SUMMARYMonoclonal antibodies reacting with pellicular antigens ofToxoplasma gondiitachyzoites have been selected among hybridomas produced against this organism by immunofluorescence assay. These antigens have been further characterized by immunofluorescence on living zoites, Western immunoblotting and immunoprecipitation of lactoperoxidase surface radio-iodinated tachyzoite lysates. The simultaneous characterization of 5 different surface antigens (P43, P35, P30, P23, P22) some of which have already been studied individually allowed a better definition of these antigens and the characterization of a yet undescribed surface molecule (P23).
Schizotrypanum in British bats
Authors: Gardner R. A. , Molyneux D. H. 
Published: June 2009

SUMMARYTwo species of Schizotrypanum, T. (S.) dionisii and T. (S.) vespertilionis, were identified from British bats. Laboratory studies on stocks of isolated trypanosomes from 5 species of bat (Pipistrellus pipistrellus, Nyctalus leisleri, N. noctula, Eptesicus serotinus and Myotis brandti) indicated that the predominant species was T. d. dionisii. Collections and dissection of the bat bug Cimex pipistrelli from bat roosts revealed flagellate infection in a total of 12 out of 20 bugs; 7 of these bugs had metacyclic trypanosomes present. C. pipistrelli and the human bed bug, C. lectularius were reared in the laboratory and allowed to feed on wild-caught bats known to be infected with T. d. dionisii. Development occurred in both species of Cimex. Cimex spp. could be used to detect subpatent Schizotrypanum infections by xenodiagnosis. This technique was used to test the parasitological status of bats collected in the wild or reared in captivity. On a single occasion an apparent transmission of T. d. dionisii to an uninfected (by xenodiagnosis) laboratory reared bat was achieved. A stock of Schizotrypanum isolated from a wild-caught C. pipistrelli collected in a N. leisteri roost was identified by DNA buoyant density centrifugation as T. (S.) vespertilionis. A P. pipistrellus known to be infected with T. d. dionisii was found to have cyst-like structures in thoracic skeletal muscle containing amastigotes. The study provided the strongest evidence yet that C. pipistrelli is the vector of Schizotrypanum in British bats.
DNA base composition of filarial nematodes
Authors: Rothstein N. , Stoller T. J. , Rajan T. V. 
Published: June 2009

SUMMARYWe have determined the molar content of guanine + cytosine (GC content) of DNA of the filarial nematode (Brugia malayi, Brugia pahangi and Dirofilaria imitis) and of the free-living soil nematodes Caenorhabditis elegans and have analysed the DNA for the presence of methylcytosine. Two independent methods, thermal denaturation and direct analysis of base content by HPLC following enzymatic hydrolysis, reveal that the GC content of filarial nematodes is 26–28%. We have been unable to find methylcytosine in the DNA of B. malayi.