bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular phylogenetics of the four Schistosoma species groups determined with partial 28S ribosomal RNA gene sequences
Authors: Littlewood D. T. J. , Johnston D. A.
Published: June 2009

Partial 28S ribosomal RNA (rRNA) gene sequences, including the variable domains D1, D2 and D3, were determined for representative species from the 4 Schistosoma species groups. On an alignment of 1345 bp from S. mansoni, S. haematobium, S. spindale and S. japonicum (with Heterobilharzia americana chosen as an outgroup), both maximum likelihood and maximum parsimony analyses provide a robust molecular phytogeny for the genus; ((((S. haematobium, S. spindale), S. mansoni), S. japonicum), H. americana). When analysed separately, both domain D1 and domain D2 yielded similarly informative data whereas D3 failed to resolve the phylogeny. These results confirm a phylogeny previously suggested by 18S rRNA gene sequences, corroborating the status of S. spindale as a sister taxon to S. haematobium, and demonstrate the utility of 28S rRNA gene sequence data for resolving phylogenies within the Schistosomatidae.

Note: nucleotide sequence data reported in this paper are available in the EMBL database under the accession numbers Z46503/04/05/06/21.
Schistosoma: analysis of monoclonal antibodies reactive with the circulating antigens CAA and CCA
Authors: Deelder A. M. , Van Dam G. J. , Kornelis D. , Fillié Y. E. , Van Zeyl R. J. M.
Published: June 2009

Using spleen cells of mice infected or immunized respectively with cercariae or antigen preparations ofSchistosoma mansoni, S. haematobiumorS. japonicummonoclonal antibodies (mAbs) were produced against the schistosome gut-associated antigens CAA (circulating anodic antigen) and CCA (circulating cathodic antigen). Fusions nearly exclusively produced either anti-CAA (n= 25) or anti-CCA mAbs (n= 55) with a strong isotype restriction (IgM, IgG1 and IgG3) against both antigens, the majority of anti-CAA mAbs being IgG1 and the majority of anti-CCA mAbs being IgM. The mAbs, which on the basis of their selection were reactive with multiple carbohydrate epitopes of CAA or CCA, were applied in different immunological techniques including immunofluorescence, a dot immunobinding assay and immuno-electrophoresis to study the epitope repertoire. Anti-CAA mAbs were found to be reactive with 5 different epitopes, none of which occurred as multiple epitopes on eggs. Anti-CCA mAbs, on the other hand, recognized at least 10 different epitopes, while 44% of anti-CCA mAbs recognized epitopes common to the adult worm and the egg. Both CAA-and CCA-epitopes were found to be developmentally expressed at the level of the tegument in cercariae, schistosomula and 5-day-old lung worms, but in the adult worm were primarily found in the gut. Thus, the production of panels of mAbs has not only resulted in the selection of reagents optimally performing in diagnostic immunoassays, but also allowed a more detailed study of the epitope repertoire of these important schistosome antigens.
Differentiation between culture-derived insect stages ofT. brucei,T. vivax, T. congolenseandT. simiaeusing a monoclonal antibody-based dot–ELISA
Authors: Bosompem K. M. , Assoku R. K. G. , Nantulya V. M.
Published: June 2009

A sensitive and specific nitrocellulose (NC) membrane-based dot–ELISA, utilizing a panel of monoclonal antibodies (mAbs), was developed for differentiation betweenin vitro-derivedprocyclic forms ofTrypanosoma brucei,T. congolenseandT. simiae, and epimastigotes ofT. vivax. Trypanosomes in suspension were applied onto NC membrane in dots and probed with unlabelled trypanosome species-specific mAbs. Bound mAb was revealed by enzyme labelled anti-mouse IgG and precipitable chromogenic substrate. The assay detected the aforementioned trypanosome species in both single and artificially mixed preparations. TenT. brucei, 4T. vivax, 7T. congolenseand 3T. simiaeprocyclic stocks and clones from different geographical areas were tested and identified using the specific mAbs in the dot–ELISA which had a specificity of 100%. Some of theT. brucei,T. congolenseandNannomonas-specific mAbs could detect as few as 10 trypanosomes/dot, whilst 1T. vivaxmAb was able to detect a minimum of 100 trypanosomes/dot in monospecies preparations. A concentration of 1 × 104trypanosomes/μ/dot was eventually determined as ideal for testing in the dot–ELISA. Antigen dots stored at 4 °C under desiccated conditions did not show any loss in activity for up to 90 days. However, when stored under similar conditions at room temperature (17–26 °C), theT. congolense-specific antigen remained unaffected up to 60 days, and then showed decreased activity when tested on day 90.
The induction ofTrypanosoma cruzitrypomastigote to amastigote transformation by low pH
Authors: Tomlinson S. , Vandekerckhove F. , Frevert U. , Nussenzweig V.
Published: June 2009

Following cell invasion,Trypanosoma cruzitrypomastigotes transform into amastigotes, which are the mammalian replicative forms of the parasite. Although amastigotes represent a critical stage in the life-cycle ofT. cruzi, little is known of the factors controlling trypomastigote to amastigote transformation. Kanbera et al. (1990) observed that exposure of trypomastigotes to acidic pH induced their transformation into rounded forms resembling amastigotes. We confirm their observation and, using two strains ofT. cruzi, establish that these transformants are ultrastructurally and biochemically indistinguishable from natural amastigotes. Incubation of trypomastigotes in medium at pH 5·0 for 2 h was sufficient to trigger their transformation into forms resembling amastigotes. Electron microscopical analysis confirmed that the kinetoplast structure, and general morphological features of the acid-induced, extracellular amastigotes were indistinguishable from those of intracellular-derived amastigotes. The extracellular transformation was accompanied by the acquisition of the stage-specific surface antigen of the naturally transformed amastigotes (Ssp-4), and loss of a stagespecific trypomastigote antigen (Ssp-3). Trypomastigotes incubated at neutral pH did not transform into amastigotes, and did not acquire the Ssp-4 epitope or lose the Ssp-3 epitope. Finally, acid-induced amastigotes subsequently incorporated [3H]thymidine into their DNA, indicating that the important replicative property of intracellular amastigotes is also exhibited by these in vitro transformants. This effect of low pH appears to be of physiological relevance, and acid-induced extracellular transformation appears to represent a valid experimental technique for studies of the molecular mechanisms involved in the differentiation process.
Sialic acid analysis and tritium-labelling of sialoglycoproteins of mouse erythrocytes infected withPlasmodium berghei
Authors: Howard R. J. , Seeley D. C. , Kao Vivien , Wember Margreat , Schauer R.
Published: June 2009

Schizont-infected red blood cells (SI-RBC) fromPlasmodium berghei-infected mice contain between 2 and 10 times as much sialic acid as uninfected RBC from the same blood (99–550 μg/1010RBC versus 33–65 μg/1010RBC). Total RBC samples from infected animals containing up to 63% ring- and trophozoite-infected cells had identical sialic acid contents to purified RBC samples (of < 3% parasitaemia) from the same blood (52–64 μg/1010RBC). We conclude that RBC containing immature parasites have the same sialic acid content as uninfected RBC from infected blood and that total cellular sialic acid increases during maturation to the schizont stage. Uninfected RBC from infected blood had 25–50% as much sialic acid as normal mouse RBC (33–65 μg/1010RBC versus 126 μg/1010RBC). There were no qualitative changes in RBC sialic acids, all RBC samples having 60–70%N-acetyl neuraminic acid, 30–40%N-acetyl-9-O-acetylneuraminic acid and 5–10%N-gly colylneuraminic acid. The quantitative changes we observed during infection must reflect changes in murine sialoglycoconjugates, as we have shown elsewhere that Plasmodia do not synthesize or contain sialic acids. Since the sialic acid composition of mouse serum glycoconjugates is quite different to that of the RBC fractions studied here, the quantitative data suggest that part of the sialic acids of the uninfected RBC has been transferred to SI-RBC. With higher molar ratios of periodate to substrate than generally used, we were able to radio-isotopically label normal murine sialoglycoproteins on SI-RBC and purified uninfected RBC from infected blood by the periodate/NaB3H4method. Several new proteins were then tritiated with SI-RBC but these proteins may be intracellular and could even lack sialie acid.
Parasite-altered behaviour: is the effect of Toxoplasma gondii on Rattus norvegicus specific?
Authors: Berdoy M. , Webster J. P. , Macdonald D. W.
Published: June 2009

The effect of Toxoplasma gondii on rat behaviour was assessed in a colony of 36 free-ranging wild/laboratory hybrid rats allowed to compete freely for food and mates in a (100 m2) outdoor naturalistic enclosure. T. gondii infection had no effect on social status or mating success, both the product of costly and competitive activities. However, the propensity to explore novel stimuli in their environment was higher in infected than uninfected individuals. These results are consistent with the hypothesis that T. gondii only affects the behavioural traits which selectively benefit the parasite, rather than causing a general alteration of rat behaviour.
Effects of endotoxin and dexamethasone on cerebral malaria in mice
Authors: Neill A. L. , Hunt N. H.
Published: June 2009

CBA/T6 and DBA/2J mice inoculated withPlasmodium bergheiANKA (PbA) develop cerebral involvement 6–8 days post-inoculation, from which the CBA mice almost invariably die and the DBA mice recover. Dexamethasone (DXM; 80 mg/kg) given to inoculated CBA mice twice, on day 3 and again within 48 h, reduced the cerebral symptoms and prevented death from cerebral malaria. Plasma tumour necrosis factor (TNF) levels, which increased at the time of the cerebral symptoms, were also reduced in these DXM-treated mice. Intravenously administered Evans Blue, a dye which binds to albumin, diffused extensively across the blood-brain barrier only during the period of cerebral symptoms, in proportion to the severity of the cerebral symptoms and the disease. In PbA-infected CBA mice, cerebral symptoms and the amount of Evans Blue diffusing into the brain tissue were both reduced by DXM treatment, but only if the steroid was given on day 3 and again within 48 h. Endotoxin injected intravascularly into PbA-infected DBA mice after day 5 resulted in an exaggeration of cerebral symptoms and death between days 6 and 9. Plasma TNF and the amount of Evans Blue in the brain parenchyma increased above normal levels in these mice. Endotoxin injections had only minor effects on the severity of the cerebral symptoms in PbA-infected CBA mice and did not cause the animals to die sooner.
A quick-frozen, freeze-fracture and deep-etched study of the cuticle of adult forms ofStrongyloides venezuelensis(Nematoda)
Authors: Martinez A. M. B. , De Souza W.
Published: June 2009

The cuticle of adult forms ofStrongyloides venezuelensiswas studied by routine transmission electron microscopy, conventional freeze-fracture and also using quick-freeze and deep-etch techniques. In routine thin sections the cuticle ofS. venezuelensiscomprises 7 layers: epicuticle, outer cortical, inner corticcal, external medial, internal medial, fibrous and basal. Observation of replicas of specimens fractured across the thickness of the body wall, revealed at the epicuticle an ordered array of particles accompanying the cuticular annulations. At the level of the cortical and medial layers we observed few scattered particles embedded in an amorphous matrix without a particular arrangement. The fibrous layer was represented by several parallel lines of ordered particles of similar size. In tangentially fractured specimens, the epicuticle cleaves readily exposing 2 faces, one exhibiting intramembranous particles without any particular arrangement, immersed in a smooth matrix (P face), and the other showing depressions and very few particles (E face). In replicas of fractures submitted to etching, we observed at the level of the cortical, medial fibrous and basal layers an interconnecting fibrous and globous structure which was organized in a different direction at the fibrous layer. The association of freeze-fracture to deep-etch technique revealed the internal structural organization of the cuticle layers showing details that were not seen before using conventional freeze–fracture technique.
Ecology of anti-microbials produced by bacterial associates ofSteinernema carpocapsaeandHeterorhabditis bacteriophora
Authors: Jarosz J.
Published: June 2009

Based on the ability of bacterial associates of entomopathogenic nematodes to produce antibiotic compounds on artificial media, it has been commonly accepted thatXenorhabdussp. andPhotorhabdussp. inhibit a wide range of invading microorganisms in insects infected withSteinernemaspp. orHeterorhabditisspp. Therefore, the question of whether antibiotic compounds produced by the primary form of bacterial symbionts associated mutualistically withS. carpocapsaeandH. bacteriophoraexplain why insect carcasses do not putrefy but provide nutritional requirements for insect parasitic rhabditoid nematodes to complete their life-cycle was examined. Laboratory bioassays of anti-bacterial activity on nutrient agar and during parasitism in larvae ofGalleria mellonellahave confirmed earlier observations thatin vitrocolonies of the primary form ofX. nematophilusandP. luminescensproduced agar-diffusible antibiotic compounds of a broad spectrum of anti-bacterial activity; their role in parasitism seems doubtful, however. This hypothesis is supported by a low antibiotic potency of a limited spectrum of anti-bacterial activity throughout the life-cycle of the parasites, principally inGalleriainfected withS. carpocapsae. Since the lack of putrefaction cannot be explained simply by antibiotic inhibition of contaminating bacterial microflora, other competition mechanisms must be operating in parasitized insects. I postulated that a rapid and massive colonization of the insect body by nematophilic bacteria creates unfavourable conditions for the growth and multiplication of bacterial (proteolytic) contaminators making the insect carcass decay-resistant. In the case ofH. bacteriophora, low antibiotic activity at an early stage of parasitism could support the colonization byP. luminescensof the host.
Selection alters the pattern of emergence from the host cadaver in the entomopathogenic nematode, Steinernema glaseri
Authors: Stuart R. J. , Lewis E. E. , Gaugler R.
Published: June 2009

We used selection to test for a genetic component to the pattern of emergence of infective juveniles from the host cadaver in the entomopathogenic nematode, Steinernema glaseri (Steiner), and whether other traits would respond to selection on this major and complex life-history character. We selected for early (‘ fast’) and late (‘ slow’) emerging lines by perpetuating nematodes that emerged on the first and after the seventh day of emergence respectively. After 12 cycles of selection, the pattern for the slow line but not the fast line differed significantly from the base population. Cumulative emergence for the slow line was less than the base population from Days 4 to 14 of the 18-day emergence period. The maximum difference occurred on the fourth day when 72·6% of emergence was complete for the base population but only 55·4% for the slow line. Decreases in infective juvenile size over the emergence period were consistent with the change in emergence pattern, but variation in sex ratios was not. No differences in infectivity were found. These results indicate that the emergence pattern has a genetic component, and that genetic variability for this trait occurs in natural populations. Furthermore, the asymmetric response to selection suggests that our field population is under strong selection for a highly skewed early emergence.
The effect of proteases and iodination on the adherent behaviour of Plasmodium falciparum-infected erythrocytes
Authors: Crandall I. , Demers D. , Sherman I. W.
Published: June 2009

Plasmodium falciparum-infected erythrocytes were treated with proteases (trypsin, chymotrypsin, pronase, or V8 protease) or iodinated and the effect of these treatments on the cytoadherent behaviour of the cells was determined. As previously observed, protease treatment reduced cytoadherence. However, it was also found that the P. falciparum-induced adhesin, pfalhesin, was not removed by protease treatment. Gelatin flotation experiments and scanning electron microscopical examination of the treated cells indicated that protease exposure resulted in changes in the knob structures on the cells, which are known to affect the adherent behaviour of the cells. Iodination was found to be an effective method of inactivating pfalhesin.
Parasite-altered behaviour: impact of infection and starvation on mating inBiomphalaria glabrata
Authors: Rupp J. C.
Published: June 2009

Very little is known about parasite-altered mating behaviour. This paper describes two experiments on the impact of infection and starvation on mating inBiomphalaria glabratasnails. In the first experiment, snails were infected with the parasitic trematodeSchistosoma mansoni. During both the early and the late stages of infection, snails were allowed to mate with individuals of the same infection status and uninfected controls. Their mating activities were filmed and later analysed. The mating frequencies of patently infected (shedding) snails were found to be lower than those of controls. This is thought to result from stress induced by the pathology. Successfully infected snails were found to mate more often as males than as females. This is seen as a compensation for the reduced fecundity caused by trematode infection. Successfully infected snails also exhibited partner choice. More matings were found between snails of the opposite infection status than among snails of the same infection status. This may be explained by the good genes hypothesis and can be seen as a specific response to schistosome infection. In the second experiment, starved snails were allowed to mate with starved and control snails. They mated less often than controls and more often as males than as females, controls showing the opposite pattern. This may be considered to be a general stress response. No partner choice has been found with starved snails. It is suggested that partner choice in infected snails occurs in response to specific rather than general stress.
Neutrophil granule proteins: evidence for the participation in the host reaction to skin microfilariae ofOnchocerca volvulusafter diethylcarbamazine administration
Authors: Gutiérrez-Peña E. J. , Knab J. , Büttner D. W.
Published: June 2009

The participation of neutrophil granulocytes in the cellular reaction to skin microfilariae ofOnchocerca volvuluswas studied by immunohistochemistry. Skin biopsies were obtained from adult Liberian and Ugandan patients with generalized onchocerciasis after exposure to topically applied diethylcarbamazine (DEC) and from untreated patients. After DEC many damaged microfilariae were observed either in dermal infiltrates or in epidermal microabscesses consisting both of neutrophils and eosinophils. Infiltrates and microabscesses contained some intact granulocytes and many neutrophils releasing myeloperoxidase, elastase, lactoferrin, defensin, lysozyme, α1-antitrypsin and α1-antichymotrypsin. Eosinophils discharged peroxidase and cationic proteins. Released granule proteins and remnants of disrupted granulocytes were found on the surface and in close proximity of damaged microfilariae in dermal infiltrates and epidermal microabscesses. In larger microabscesses neutrophils were predominant. These observations show that neutrophils and not only eosinophils recruit, accumulate, localize around and release their helminthotoxic granule proteins such as myeloperoxidase onto or closely around skin microfilariae ofO. volvulusafter topical DEC administration. The association between these processes and the damage of the microfilariae indicated that neutrophils together with eosinophils attack and damage microfilariae ofO. volvulusafter DEC treatment in the skin.
Hymenolepis diminuta: metacestode-induced reduction in the synthesis of the yolk protein, vitellogenin, in the fat body of Tenebrio molitor
Authors: Webb T. J. , Hurd H.
Published: June 2009

Vitellogenin synthesis by the fat body has been monitored using in vitro culture and immunoprecipitation. This system was found to be efficient for measuring vitellogenin production in both non-infected Tenebrio molitor and those infected with Hymenolepis diminuta. In fat bodies from infected beetles, vitellogenin production was decreased by up to 75% (day 24 post-infection) and, at all times investigated, vitellogenin synthesis was significantly below control levels (days 3–30 post-infection). Incubating fat bodies from control insects with isolated metacestodes indicated that this may be a direct effect by the parasite which is developmental stage-specific. Stage II, but not stage III–IV, nor heat-killed parasites could bring about this decrease in vitellogenin. In addition, these effects may be density dependent within the range of 2–20 parasites per fat body; only 2 metacestodes were necessary to cause a significant decrease. Since metacestodes do not take up vitellogenin, nor limit the amount of [14C] leucine available to the fat body for vitellogenin production, it is conceivable that the parasite produces a potent inhibitor of vitellogenin synthesis, or a molecule which induces cells within the fat body to do so.
Species-specific DNA probes for the identification of African trypanosomes in tsetse flies
Authors: Gibson W. C. , Dukes P. , Gashumba J. K.
Published: June 2009

We have obtained 5 specific DNA probes for African trypanosomes of the subgenera Trypanozoon and Nannomonas. Each probe consists of one repeat unit of the major repetitive DNA (satellite DNA) of each species or intra-specific group. One probe hybridized with all members of subgenus Trypanozoon (except T. equiperdum which was not tested). In subgenus Nannomonas, one probe recognized T. simiae, but 3 probes were needed to identify all stocks of T. congolense available. Each of the 3 latter probes recognized trypanosomes from one of the 3 major groups of T. congolense previously defined by isoenzyme characterization, i.e. savannah, forest and Kenya coast types. As few as 100 trypanosomes could be unequivocally identified by dot blot hybridization and individual trypanosomes could be identified by in situ hybridization. We show how this simple methodology can be used in the field for the identification of immature and mature trypanosome infections in tsetse.
Hymenolepis nana: the fine structure of the embryonic envelopes
Authors: Fairweather I. , Threadgold L. T.
Published: June 2009

The fine structure of the envelopes surrounding hatched and unhatched oncospheres of Hymenolepis nana has been investigated by transmission and scanning electron microscopy (SEM), together with light microscope histochemical observations of JB-4 embedded material. The oncosphere is surrounded by 3 layers – the capsule, the outer envelope and the inner envelope, the latter giving rise to the embryophore and the ‘oncospheral membrane’. An additional layer – the polar filament layer – lies between the ‘oncospheral membrane’ and the oncosphere. Shell material is deposited on the capsule as a thin layer. It is secreted by the outer envelope, which degenerates once shell formation is complete. The uterus may also contribute to shell formation. The embryophore forms a thin, incomplete and peripheral layer within the inner envelope. In the basal region of this envelope, partial development of an ‘oncospheral membrane’ takes place, but it does not become detached as a separate layer. The polar filaments, which are characteristic of the oncosphere of H. nana, are derived from the epithelial covering of the oncosphere itself, which delaminates to form a separate polar filament layer. The filaments arise from knob-like projections at opposite poles of this layer. The design of the embryonic envelopes in H. nana show a number of modifications from the basic cyclophyllidean pattern, and these can be related to the demands of its ‘direct’ life-cycle.
Polymorphism inPlasmodium vivaxMSA1 gene – the result of intragenic recombinations?
Authors: Cheng Q. , Stowers A. , Huang T.-Y. , Bustos D. , Huang Y.-M. , Rzepczyk C. , Saul A.
Published: June 2009

The diversity in a 925 bp portion of thePlasmodium vivaxMSA1 gene in isolates from the Philippines, China, the Solomon Islands and Papua New Guinea was investigated. A total of 74 base pair changes was found in the amplified fragment from 18 isolates. Most of these changes were single or double base pair substitutions. In several regions, these point changes were tightly linked with one set always present or always absent in the different isolates. Seven such blocks were identified. These blocks were present in different combinations in the different isolates indicating that extensive intragenic recombination has occurred.
Experimental evidence of genetic determinism in high susceptibility to intestinal pinworm infection in mice: a hybrid zone model
Authors: Moulia C. , Brun N. Le , Dallas J. , Orth A. , Renaud F.
Published: June 2009

In the hybrid zone of the two mouse subspecies Mus musculus musculus and Mus musculus domesticus, mice with hybrid genotypes harbour, on the average, more helminth parasites (cestodes and nematodes) than mice of the two parental taxa. In order to determine the roles played by genetic parameters in this phenomenon, mice with recombined and parental genotypes were experimentally infected with the intestinal pinworm Aspiculuris tetraptera, a natural parasite of the house mouse. The results showed that the high susceptibility of the hybrid zone mice is genetically determined. In addition, this study shows the occurrence of variability among resistant parental populations.
An ion-sensitive microelectrode study on the effect of a high concentration of ivermectin on chloride balance in the somatic muscle bag cells of Ascaris suum
Authors: Parri H. R. , Djamgoz M. B. A. , Holden-Dye L. , Walker R. J.
Published: June 2009

Ivermectin has been shown to increase chloride conductances of invertebrate cells. On the muscle cells of the parasitic nematode Ascaris, ivermectin acts as both a GABA receptor antagonist and a chloride channel opener. In this study, ion-sensitive microelectrodes were used to investigate the effect of ivermectin on intracellular C1− concentration of the somatic muscle bag cells of Ascaris suum. Incubation of muscle cells with ivermectin (10 μM in 1% dimethyl sulphoxide vehicle for 60 min) increased intracellular C1− by 2·9 mM or 15% compared to controls (P > 0·01, n = 6).
The cholinergic, serotoninergic and peptidergic components of the nervous system ofMoniezia expansa(Cestoda, Cyclophyllidea)
Authors: Maule A. G. , Halton D. W. , Shaw C. , Johnston C. F.
Published: June 2009

The central (CNS) and peripheral (PNS) nervous systems of the cyclophyllidean tapeworm,Moniezia expansa, were examined for the presence of cholinergic, serotoninergic and peptidergic elements using enzyme cytochemical and immunocytochemical techniques in conjunction with light and confocal scanning laser microscopy. Cholinesterase activity and 5-hydroxytryptamine- and regulatory peptide-immunoreactivities (IRs) were localized to the nerve fibres and cell bodies of all of the major neuronal components in the CNS of the worm, including the cerebral ganglia and connecting commissure, the 10 longitudinal nerve cords and associated transverse ring commissures. Although each of the 3 systems appeared well developed and comprised a significant portion of the nervous system, the serotoninergic constituent was the most highly developed, consisting of a vast array of nerve fibres and cell bodies distributed throughout the strobila of the worm. A close association of cholinesterase reactivity and peptide-IRs was evident throughout the CNS, indicating the possible co-localization of acetylcholine and neuropeptides. Within the PNS, cholinergic activity and serotoninergic- and peptidergic-IRs occurred in the subtegumental network of nerve fibres and somatic musculature. Although all 3 neuro-chemical elements were present in the acetabula, they were found in different nerve fibres; only cholinergic and peptidergic cell bodies were found. The common genital opening, vagina and ootype regions of the reproductive system displayed a rich innervation of all 3 types of neuronal populations. Within the peptidergic system, immunostaining with antiseraraised to the C-terminus of the neuropeptide Y superfamily of peptides and the invertebrate peptides, neuropeptide F (M. expansa) and FMRFamide was the most prevalent. Limited positive-IR for substance P and neurokinin A were also recorded in the CNS of the worm.
Experimental transmission of Schistosoma mansoni in brackish waters
Authors: Chernin Eli , Bower Carol
Published: June 2009

In the laboratory, transmission of Schistosoma mansoni to and from Biomphalaria glabrata can occur in artificial sea water at or below a concentration of 12-5%. Miracidia can also emerge and infect snails in 25 % sea water, but this concentration is inimical to the survival of the snails or their eggs. The parasite thus appears to be better adapted to brackish water than is the intermediate host. Epidemiological studies are needed to assess the limits imposed by brackish waters on the natural transmission of schistosomiasis.
The form and function of the oesophageal region of the insect parasite Tetradonema plicans (Nematoda: Tetradonematidae)
Authors: Elaine Hudson K.
Published: June 2009

The tetrad and companion cells, in association with the oesophagus and dorsal tract of tissue, of Tetradonema plicans, have been investigated in the host Bradysia paupera. The companion cells contain glycogen and mucopolysaccharide. The tetrad cells are rich in RNA and probably synthesize protein and secrete some as enzymes. The gut is functional and the oesophagus is in connexion with the tetrad. The dorsal tract is not connected with the oesophagus or tetrad and contains lipid with characteristics similar to that found in the eggs.

It is suggested that the tetrad and companion cells are homologous with the stichocytes present in the Trichuroidea and some members of the Mermithoidea.

I am grateful to Professor T. R. E. Southwood in whose department this work was carried out. I should like to thank Dr N. A. Croll for supervising and encouraging this work and Dr T. Jenkins for his helpful criticism and advice. The work was supported by the Agricultural Research Council.
The stability of resistance to diminazene aceturate and quinapyramine sulphate in a strain ofTrypanosoma vivaxduring cyclical transmission through antelope
Authors: Gray A. R. , Roberts C. J.
Published: June 2009

A drug-resistant strain ofT. vivaxwas transmitted through a series of four duikers (S. grimmia) and a gazelle (G. rufifrons) byG. palpalisandG. tachinoides. The cyclical transmission of the strain in cattle, started in earlier work, was continued for control purposes. Infections with the drug-resistant strain in the antelope were of the same type as those produced by field strains ofT. vivaxin the same host species, and infection rates in tsetse flies fed at early stages of infection on the antelope were similar to those found in flies fed on cattle infected with the drug-resistant strain. The strain retained resistance to diminazene aceturate at a dose rate of 7-0 mg/kg and quinapyramine sulphate at 5'0 mg/kg in the absence of the drugs for 7 months in tsetse flies and antelope, and for a total period of 29 months in tsetse flies and cattle.

We wish to thank Dr A. A. Amodu, Director of the Nigerian Institute for Trypanosomiasis Research, for permission to publish this paper.
Polymerase chain reaction—identification of Dirofilaria repens and Dirofilaria immitis
Authors: Favia G. , Lanfrancotti A. , Torre A. Della , Cancrini G. , Coluzzi M.
Published: June 2009

On the basis of known DNA sequences of Dirofilaria repens and D. immitis we designed specific primers for the amplification by Polymerase Chain Reaction (PCR) of the DNA from the two species. The PCR-based identification was found to be unambiguous and allowed specific diagnosis of microfilariae in blood samples, of developing larvae in the mosquito vector and of immature adults in bioptic material, overcoming the serious constraints of the morphological separation of these filarial parasites at the pre-adult stages. The technique was found to be very sensitive and applicable to samples stored either dry or in various preservation media, with the exception of formalin. The reliable identification of D. repens and D. immitis from bioptic material is expected to greatly enhance the chances of detecting human infections and to further clarify the role of the two parasites as pathogens of man. The possibility of routine identification of developing larvae in the vector will substantially improve the perspectives for epidemiological investigations, particularly in Southern European regions, such as Italy, where the two nematode species are largely sympatric.
Cytoskeleton-associated antigens from African trypanosomes are recognized by self-reactive antibodies of uninfected mice
Authors: Müller N. , Imboden M. , Detmer E. , Mansfield J. M. , Seebeck T.
Published: June 2009

Serum from uninfected mice of different strains, as well as from germ-free animals, contains antibodies which react specifically with at least two trypanosomal proteins, I/6 and MARP1. These antibody populations are highly specific for the respective proteins, are of similar affinity as hyperimmune antibodies, and consist of IgM as well as IgG isotypes. Hyperimmune antibody raised against the cross-reacting trypanosomal protein I/6 detects a 60 kDa protein in mouse 3T6 cells, which is a component of the fibroblast cytoskeleton.
Changes in host muscles induced by excretory/secretory products of larvalTrichinella spiralisandTrichinella pseudospiralis
Authors: Ko R. C. , Fan L. , Lee D. L. , Compton H.
Published: June 2009

Excretory/secretory (ES) products obtained byin vitroculture of infective-stage larvae ofTrichinella spiralisandT. pseudospiraliswere injected intramuscularly at various intervals into mice. Mini-osmotic pumps containingT. spiralisES products were also implanted subcutaneously and intraperitoneally into rats. The introduction of ES materials into muscles elicited extensive lesions which included dissolution of myofibres, mobilization of mononuclear and polymorphonuclear leucocytes, angiogenesis, hypertrophy of myonuclei, myotube formation, mitosis, muscle bundles becoming rounded and separated from each other, disappearance of Z, I and A bands of sarcomeres, increase in endoplasmic reticulum and Golgi complexes, decrease in glycogen and relocation of mitochondria. These are considered as degenerative/regenerative changes of muscles to injury. Immunodominant epitopes of specific 45–53 kDa glycoproteins in ES antigens ofT. spiraliscould not be detected in hypertrophic nuclei of injected muscles by using polyclonal and monoclonal antibodies and immunocytochemical methods. ES products ofT. spiralisfailed to stimulate unsensitized lymphocytes in the lymphocyte transformation test. Infective-stage larvae ofT. spiralisreleased from muscles were found capable of forming nurse cells after injection subcutaneously into rats. It is postulated that the invasion of muscles by trichinellids elicits two independent events, i.e. a general degenerative/regenerative response of muscles and a specific change in genomic expression of myonuclei. The two events are probably mediated by different effector molecules.
The control of trichostrongyle larvae (Nematoda) by fumigation in relation to their bionomics
Authors: Sturrock R. F.
Published: June 2009

A standard culture technique is described for obtaining the various developmental stages of Trichostrongylus colubriformis, and a suitable technique for assessing the effect of methyl bromide fumigations is outlined.

Doses of 10, 25 and 150 mg. hr./l. were required to give an LD50 for eggs, pre-infective and infective larvae respectively. The age of infective larvae, the relative humidity and the temperature all influenced the toxicity of the fumigant. Soil, and more especially faeces, sorb the fumigant and probably protect larvae from its full effect. Infective larvae of T. axei, T. retortaeformis and H. contortus were also found to be susceptible to methyl bromide.

The activity of larvae surviving fumigation was considerably reduced, but these larvae were still capable of infecting guinea pigs.

Methyl bromide killed common pasture grasses at doses of 150–250 or more mg. hr./l., depending on the temperature. Chloropicrin was found to be highly toxic to grass and unsuitable where the pasture is required undamaged.

The results are discussed in the light of current theories of the mode of action of methyl bromide on insects and what is known at present of the physiology of nematodes.

It is concluded that under certain conditions, methyl bromide might be used to eliminate infestations of trichostrongyle larvae on pasture, without killing the pasture.

I am indebted to Professor B. G. Peters and other members of the staff of the Imperial College Field Station and Dr C. W. R. Spedding of the Grassland Research Institute, Hurley, for their help in this work and their advice and criticism.
On a new trematode Echinoparyphium bagulai sp.nov., (Echinostomatidae) from Anas poecilorhyncha
Authors: Jain G. P.
Published: June 2009

In November 1953, about one-half per cent of Lymnaea luteola taken from a pond in Alfred Park, Allahabad, were infected with an echinostome cercaria. The first collections of these cercariae were made by Dr Onkar Nath Srivastava, who was surveying cercarial infections in the snails and who kindly gave me the echinostome material. Additional material was obtained by numerous subsequent collections. After the cercaria was described it was possible to undertake a limited number of experiments in an attempt to discover other stages of the life cycle. It was found that Lymnaea luteola is both the first and the second intermediate host of a new species of Echninoparyphium. The adult of this new species, for which the name E. bagulai is proposed, matures in the intestine of the domestic duck, Anas poecilorhyncha. When this duck was experimentally infected with cercariae, the adult trematode was recovered from the intestine of this duck 21 days after its infection.
Structure and function in the nematode pharynx
Authors: Mapes C. J.
Published: June 2009

The simple cylindroid pharynx ofAscaris lumbricoideshas been shown to be characterized by a pharyngo-intestinal valve which is composed of two sets of valves. This is the only valve structure in the pharynx of this nematode. The pharynges ofOxyuris equi, Aplectana brevicaudataandPanagrellus silusiaehave a series of valve structures along the lengths of the organs. All these types have a valve at the anterior end of the corpus, corrugated ‘valves’ in the posterior bulb, and pharyngo-intestinal valves. A valve between the corpus and the isthmus has been shown inOxyuris.

In all the nematodes studied the pharyngo-intestinal valve is characterized by an overlapping of the muscle fibres associated with the valve and the main musculature of the pharynx that immediately precedes them. It has been suggested that the pharyngo-intestinal valves of the types studied may have evolved from the type of valve found in the Enoplina.

The marginal tissues of the pharynx ofAscaris lumbricoideshave been shown to be composed of three types of tissues. It has been suggested that the marginal tissues have a suspensory and skeletal function. The suspensory strands subserve the first function, while the investing strands and the associated fibrous layer provide a longitudinal skeletal structure in the pharynx. InOxyurisno fibrous layer is associated with the marginal tissues.

I would like to thank Professor J. E. Harris and Dr H. D. Crofton for their help and criticism during the course of this work, which was carried out during the tenure of a Postgraduate Studentship awarded by the Agricultural Research Council.
The physiology of excystment of the metacercaria ofFasciola hepaticaL.
Authors: Dixon K. E.
Published: June 2009

Excystment of the metacercaria ofFasciola hepaticais an active process and occurs in two stages—activation and emergence. Activation is initiated by high concentrations of carbon dioxide, reducing conditions and a temperature about 39 °C. The reducing conditions increase the rate of action of the other two stimuli. The carbon dioxide stimulus need only be applied for 5 min, but the exposure time to the reducing conditions has to be of the order of 30 min. Changes in the order of application of the stimuli carbon dioxide and redox potential have no effect.

The second phase, emergence, is triggered by bile. Metacercariae were held in an activated condition for 24 h, and when bile was added emergence took place normally.

During excystment the metacercariae exhibit a complex behaviour pattern. After activation there is an initial period of rotatory activity, but after about 20 min a quiescent phase ensues when the metacercariae contract away from the cyst wall at an imperceptible rate. This behaviour occurs in response to stimulus from a high concentration of carbon dioxide and a temperature about 39 °C. When the metacercariae are exposed to bile the second phase of activity is initiated, consisting of antero-posterior thrusting movements directed against the ventral side of the cyst wall. Within about 15 min the juvenile flukes escape through a small circular hole in the ventral surface of the cyst wall which corresponds to the ventral plug region.
The fate of the sporozoites of Eimeria acervulina, Eimeria maxima and Eimeria mivati in the caeca of the fowl
Authors: Horton-Smith C. , Long P. L.
Published: June 2009

The sporozoites of Eimeria acervulina and E. maxima when injected into the caeca of chickens fail to produce infections. Sporozoites of E. mivati injected into the caeca invade the walls and the life-cycle is completed. These observations are discussed in their relation to the fate of sporozoites injected into the allantois of chick embryos. The possible use of these techniques in confirming the identity of a species is discussed.

We wish to thank Mr B. J. Millard for technical assistance with the preparation of the sporozoites.
Small spines on the egg shells of Schistosoma
Authors: Hockley David J.
Published: June 2009

Small spines of maximum size 0.28 μm × 0.5 μm have been found all over the shells of the eggs of Schistosoma mansoni and S. haematobium. The small spines on S. haematobium eggs are less pointed than those on S. mansoni eggs. They consist of inner and outer parts made up of subunits, and they are continuous with the main part of the shell underneath. S. mansoni eggs still within the blood vessels of the gut have extracellular material between the spines and there is cell debris over them. The scanning electron microscope shows the increased surface area of the egg shell due to the small spines.

I wish to thank many people for their help with this work and in particular Dr F. Hawking, Dr S. R. Smithers and Mrs. L. Ebden.
Nematode parasites of Oceanica. IV. Oxyurids of mammals of Palawan, P.I., with descriptions of four new species of Syphacia
Authors: Schmidt Gerald D. , Kuntz Robert E.
Published: June 2009

Syphacia (Syphatineria) oceanica sp.nov. is described from the squirrel Sundasciurus steerii juvencus. It is closest to S. transafricana Chabaud & Biocca, 1955, differing from it in having a cephalic vesicle, an isthmus between oesophagus and bulb, and in characteristics of the gubernaculum. Syphacia (Syphacia) critesi sp.nov. is described from S. steerii juvencus and the flying squirrel Hylopetes nigripes. It is closest to S. thompsoni Price, 1928, differing from it in lacking cephalic vesicle, alae, and cervical papillae; in having a long oesophagus and shorter gubernaculum Syphacia (Syphacia) magnispicula sp.nov. is described from H. nigripes and S. steerii juvencus. It is characterized by having a spicule 312–338 μm long, much longer than any species yet reported. Syphacia (Syphacia) coli sp.nov. is described from H. nigripes and the rat Rattus exulans luteiventris. It is closest to S. critesi sp.nov., differing from it in sizes and shapes of oesophagus and gubernaculum, in having lateral alae, and in egg size. Syphacia sp. is reported from Rattus exulans luteiventris; Blattophila sp. is reported from the skunk Mydaus marchei; and Allodapa sp. is reported from Sundasciurus steerii juvencus.

The authors wish to express their appreciation to Dr D. S. Rabor, Silliman University, Dumageute, Negros Oriental, Republic of Philippines, for general support in field activities and for tentative host identifications; Mr Max Thompson, Bishop Museum, Honolulu, for assistance in collection of hosts and Dr David H. Johnson, Research Curator, Division of Mammals, U.S. National Museum Washington, D.C., for final host identifications. Thanks are extended to Dr W. G. Dyer and Dr P. D. Leiby, Minot State College, for technical assistance during the course of this work, and to Dr W. W. Becklund, Beltsville Parasitological Laboratory, for the loan of specimens for comparative purposes. Special thanks are due to Mrs MayBelle Chitwood, whose efforts greatly improved the quality of this work.
Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from Raja naevus with a comment on its habitat and mode of attachment
Authors: Williams H. Harford
Published: June 2009

Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from the intestine of Raja naevus in the North Sea resembles P. dagnallium, P. radioductum and P. britannicum more closely than any other known species of the genus but differs from these mainly in its host, in having distinctly bifid bothridia with faint marginal loculi and about 150 testes in each proglottid. Brief comments are made on the preference shown by the adult for the posterior region of the intestine and on a modification of its bothridium for attachment to up to 12 villi.

This work was supported by generous financial aid from the Natural Environment Research Council. I wish also to record my gratitude to Professor V. C. Wynne-Edwards and Dr P. A. Orkin for reading and suggesting improvements to the manuscript and to the Director and staff Marine Laboratory, Aberdeen, in particular Dr B. B. Rae and Mr Stuart Pirie, after whom this species has been named, for providing live rays. Alasdair McVivar of this department, who has now begun an independent study of the intestine of Raja naevus as a habitat for helminth parasites, kindly provided information for Fig. 9.
Passive protection with cells or antiserum against Nippostrongylus brasiliensis in the rat
Authors: Ogilvie Bridget M. , Jones Valerie E.
Published: June 2009

Rats can be passively protected against N. brasiliensis either with antiserum or with cells. Only some pools of antiserum (15 of 48 pools) and a few batches of cells (three of 11 batches) were protective.

Protective activity was found in serum taken after one infection as frequently as after several infections and gave the same degree of protection. This suggests that second and subsequent infections do not stimulate an anamnestic increase in protective antibodies in the circulation.

Serum and cells taken from the same rats were unrelated in their protective capacity; sometimes serum protected when the cells were ineffective and the reverse also occurred.

Cells transferred from the spleen, peritoneal cavity or mesenteric lymph nodes were capable of initiating reagin formation, irrespective of their ability to protect against N. brasiliensis.

When protection was achieved with transferred cells, the parasite life-cycle was shortened by only 1–2 days.

We have found no evidence that a delayed mechanism of the homograft type is concerned in immunity to N. brasiliensis in the rat.

We thank Miss W. D. Griffiths and Mr A. J. Edwards for their willing assistance. The statistical analysis was kindly done for us by Miss M. V. Mussett of the Statistics Department at our Institute.