bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative study on Rickettsia-like organisms in the midgut epithelial cells of differentGlossinaspecies
Authors: Shaw M. K. , Moloo S. K.
Published: June 2009

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

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

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

Two species of Eimeria isolated from jungle fowl of Malaysia were examined in infections of chickens. Eimeria diminuta reproduced well in the embryo CAM and caused severe infection of the lower small intestine and caeca of chickens, but did not develop in the duodenum. It reproduced well in chickens and severely affected their body weight gain. The endogenous stages and oocysts were similar to E. acervulina var. mivati and cross-protection tests with this parasite and E. acervulina confirmed the close relationship between them. It is suggested that the parasite should be referred to as E. acervulina var. diminuta.

The oocysts of another species examined (E. indentata) were similar to E. maxima: the parasite reproduced well in chickens, was pathogenic and showed marked cross-protection against two strains of E. maxima isolated in Britain. The name E. maxima var. indentata is suggested for this parasite.

When low immunizing doses of two strains of E. maxima isolated and maintained in Britain were given, they did not completely cross-protect against re-infection with the heterologous strain.
Independent expression of the metacyclic and bloodstream variable antigen repertoires ofTrypanosoma brucei rhodesiense
Authors: Turner C. M. R. , Barry J. D. , Vickerman K.
Published: June 2009

The variable antigen repertoire expressed by metacyclicTrypanosoma brucei rhodesienseis not influenced by the anamnestic expression whereby the variable antigen type (VAT) ingested by a tsetse fly is present at high levels in early bloodstream populations of fly-infected mice. This has been demonstrated by feeding toGlossina morsitansa trypanosome line expressing a VAT which is normally a component of the metacyclic repertoire. The VAT did not constitute a significantly increased proportion of the resultant metacyclic population which would have occurred had anamnestic expression and metacyclic expression been linked. Five other metacyclic VATs were also present at control levels. We conclude that the mechanisms of expression of VATs in the fly and in the mammal are independently controlled.
Adaptation of a radioactive L. donovani complex DNA probe to a chemiluminescent detection system gives enhanced sensitivity for diagnostic and epidemiological applications
Authors: Wilson S. M. , Mcnerney R. , Moreno M. B. , Frame I. , Miles M. A.
Published: June 2009

The cDNA probe, Lmet2, was labelled with digoxigenin and used in a chemiluminescent system to detect fewer than 100 membrane-immobilized Leishmania parasites. The probe was found to hybridize primarily with members of the L. donovani complex but a slight cross-reaction was also observed with greater than 5 x 104L. major. This cross-reaction was reduced by hybridizations in 50% formamide at 37 °C. Formamide also significantly reduced non-specific binding of the digoxigenin-labelled probe to the membrane support which, in hybridizations without formamide, masked the specific hybridization signal. This background was not observed with the corresponding radio-isotope labelled probe. With hybridizations in formamide the sensitivity achieved by the chemiluminescent system after exposure to film for 3 h was greater than that achieved by the isotopic system even after autoradiography for 24 h.
Finding and recognition of the snail intermediate hosts by 3 species of echinostome cercariae
Authors: Haas W. , Körner M. , Hutterer E. , Wegner M. , Haberl B.
Published: June 2009

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

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

The induction of schistosomulicidal activity of peritoneal macrophages by concanavalin A-stimulated supernatants from long-term T-cell clones and by interferon-gamma (IFN-γ) was investigated in detail. Optimal conditions ofin vitromacrophage activation by T-cell clone supernatants were established. Macrophages from 13-weekS. mansoni-infected mice responded to lymphokine activation as well as resident mnacrophages from uninfecteci mice. IFN-γ was shown to play an essential role in induction of schistosomulicidal macrophage activity: recombinant IFN-γ at high concentration could induce schistosomula killing, and an anti-IFN-γ antiserum inhibited the induction ofschistosomulicidal activity by T-cell clone supernatants. Our data also indicate that macrophage activation could be obtained by IFN-γ in synergy with other lymphokines in the supernatant of long-term T-cell clones. Macrophages from mice injected with T-cell clone supernatants were primedin vivoand triggered to kill schistosomula in vitro in the presence of lipopolysaccharide (LPS). The data demonstrate that lymphokines produced by T-cell clones and, in particular, IFN-γ can participate in the activation of schistosomulicidal macrophages.
Negative effect on early post-implantation pregnancy and progesterone levels in mice infected with the intestinal trematodeEchinostoma caproni
Authors: Bindseil E. , Hau J.
Published: June 2009

Infection in mice (BALB/cABom) with the intestinal trematodeEchinostoma capronihad a negative influence on pregnancy. The effect of the infection set in immediately following implantation (day 5 of pregnancy) resulting in fewer foetuses being present in infected mice on day 9 than in the controls. Ovulation, fertilization of eggs, and implantation itself were obviously not impaired. The infected mice had significantly lower serum progesterone levels on day 5 of pregnancy than the non-infected controls. It is speculated that the progesterone levels in the infected female mice were too low to secure early post-implantation gestation.
The host-parasite relationships in pyridoxine (vitamin B6) deficient cotton rats infected with Litomosoides carinii (Nematoda: Filaroidea)
Authors: Beg M. A. , Fistein J. L. , Storey D. M.
Published: June 2009

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

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

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

An open randomized study was carried out to assess the efficacy of diethylcarbamazine (DEC) and mebendazole (MBZ) across, respectively, 39 and 41 patients, all exhibiting clinical and biological features evocative of toxocariasis, together with a positive immunodiagnosis by Western blot usingToxocaralarvae excretory-secretory antigens. Clinical impact of the disease was quantified by a score system (20 parameters). Post-treatment follow-up used also results from eosinophil counts from total and specific anti-ToxocaraIgE quantitations, and from Western blots. All patients attended the control check-up 1 month after the end of treatment. Analysis of the results showed a similar good efficacy of DEC and MBZ on clinical score and eosinophil count that were significantly lowered. MBZ therapy was slightly more efficient on specific anti-ToxocaraIgE kinetics, while total IgE mean titres were not affected by either DEC or MBZ treatment. Patients from the DEC group reported a significantly higher rate of adverse reactions, most of which could be due to parasite lysis. This fact could be a strong argument for treating human toxocariasis with MBZ.
Avian coccidiosis: the administration of encapsulated oocysts
Authors: Norton C. C. , Joyner L. P.
Published: June 2009

Oocysts of fowl coccidia, suspended in a 12% aqueous solution of alginic acid, were dropped into 5% calcium chloride solution to form beads. Following ingestion by chicks, excystation of sporozoites was not affected. Oocyst viability was best when beads were air-dried to 33% of their original weight and stored in airtight containers at 4°C. Infectivity was fully maintained for 8 weeks. Trickle infection, using beads administered orally to 2- or 3-week-old chickens, or mixed daily in food of chicks from 1-day-old, established a high level of immunity. This method of oocyst administration offers some practical advantages for the conduct of immunity and chemotherapy experiments.
The epidemiology of diplostomiasis in farmed rainbow trout from north-east Scotland
Authors: Stables J. N. , Chappell L. H.
Published: June 2009

An epidemiological survey of the distribution and abundance of Diplostomum spathaceum in farmed rainbow trout (Salmo gairdneri) from Mill of Cantray trout farm (Nairn, Morayshire) involved monthly sampling of fish over a 3-year period. Diplostomurn metacercariae were present in both the lens and aqueous humour of infected fish, and these have been treated separately throughout the study. The infection period was normally between May and September each year and transmission of the parasite from snail to fish did not occur at temperatures below 10°C. The prevalence and abundance of both lens and humour metacercariae reached a maximum in September. The cleansing and application of a molluscicide (copper sulphate) to the raceways in spring resulted in a 56% reduction in the numbers of metacercariae infecting trout during the following summer. However, no further improvement in parasite control was recorded when the treatment was repeated in the following year. Experiments using caged fish indicated that diplostomiasis was confined to certain areas of the farm only and that the infection rate of rainbow trout with D. Spathaceum cercariae was correlated (P < 0·01) with water temperature. The results of the study indicated that it is possible by regular cleaning and use of molluscicides to keep the intensity of diplostomiasis at such a level that rainbow trout do not become severely affected. However, as with other parasitic diseases, a combination of control methods will probably be required to eradicate the disease completely from trout farms.
Strain differentiation of Onchocerca volvulus from Uganda using DNA probes
Authors: Fischer P. , Bamuhiiga J. , Kilian A. H. D. , Büttner D. W.
Published: June 2009

Polymerase chain reaction (PCR) combined with non-radioactive DNA hybridization was applied for the detection and characterization of a 150 bp tandem repeat of Onchocerca volvulus. DNA of worms from western Uganda was amplified and then probed with a digoxygenin-labelled oligonucleotide, specific for the forest form of O. volvulus and compared to samples from various African countries. Hybridization was only observed with PCR products from the forest in Liberia, south-eastern Ghana, Benin and southern Cameroon, but not with worms from Uganda or the savannah in Burkina Faso and northern Ghana. A nested PCR using primers derived form the forest form-specific DNA sequence confirmed these results. Morphometric studies revealed length differences between the microfilariae of Ugandan O. volvulus to those of West Africa, especially to those of the savannah in Burkina Faso. It is concluded that the forest/savannah classification of O. volvulus from West Africa is not suitable for Simulium weasel-transmitted O. volvulus from Uganda.
Efficacies of vaccines against canine hookworm disease
Authors: Vinayak V. K. , Gupta N. K. , Chopra A. K. , Sharma G. L. , Kumar Asha
Published: June 2009

Three types of vaccine (1) a sonicated extract of killed larvae, (2) 5-fluorouracil-treated larvae and (3) 40 krad. X-irradiated larvae have been evaluated. Pups aged 3–4 months, weighing 2± 0·5 kg and free of natural hookworm infection were selected for experimental studies. The sonicated extract was given either in a single dose or as 2 doses at weekly intervals, whereas the 5-fluorouracil-treated and X-irradiated larvae were given in a single dose only. After completion of the vaccination schedule, the pups were challenged with filariform larvae and were sacrificed 3 weeks after challenge. Non-vaccinated pups and those vaccinated with a single dose of sonicated extract lost weight and had diarrhoea or dysentery after challenge. Furthermore, in non-vaccinated pups, haemoglobin levels fell and at autopsy the intestinal mucosa was found to be grossly congested and free blood was present in the lumen of the intestine. Such findings were not obtained in pups vaccinated with the other types of vaccines. The percentage of infective larvae which developed to the adult stage in non-vaccinated pups was 82·7 ± 9·53 compared with 45·1 ± 12·33, 30·1 ± 10·05, 20·6 ± 10·60 and 8·0 ± 7·46 %, respectively in pups vaccinated with a single dose of sonicated extract, double dose of sonicated extract, 5- fluorouracil-treated and 40 krad. X-irradiated larval vaccines. While the irradiated larval vaccine provided maximum protection against clinical ancylostomiasis, 2 doses of the sonicated larval vaccine could also afford almost equal protection to pups.
Small subunit (18S) ribosomal RNA gene divergence in the genus Schistosoma
Authors: Johnston D. A. , Kane R. A. , Rollinson D.
Published: June 2009

An entire 18S rRNA gene sequence from Schistosoma spindale (1990 bases) and partial 18S rRNA gene sequences from S. haematobium (1950 bases) and S. japonicum (1648 bases) have been determined. Together with the previously published sequence for the S. mansoni 18S rRNA gene, these data encompass the 4 recognized Schistosoma species groups. Although Schistosoma 18S rRNA genes are highly conserved, the sequences permit a preliminary molecular phylogeny to be established for the genus. This identifies S. haematobium and S. spindale as sister taxa in a clade with S. mansoni. S. japonicum does not appear to be closely related to this clade. Much of the observed variation occurs within a ‘hypervariable’ stretch of the gene corresponding to part of the V4 region of 18S rRNA. Despite this variation, the 3 new sequences fit models of 18S rRNA secondary structure predicted from the S. mansoni sequence.

The sequences reported in this paper have been submitted to the EMBL Database under accession numbers Z11976 (S. haematobium), Z11590 (S. japonicum) and Z11979 (S. spindale).
Identification and in situ and in vitro characterization of secreted proteins produced by plant-parasitic nematodes
Authors: Curtis R. H. C.
Published: June 2009

Secretions of plant-parasitic nematodes which are released into plant tissue may play critical roles in plant-nematode interactions. The identification and characterization of these molecules are of fundamental importance and may help to facilitate the development of novel strategies to interfere with nematode infection of plants and thereby decrease nematode-induced damage to crops. An antibody-based approach was used to isolate molecules present on the nematode surface and in nematode secretions. Monoclonal antibodies (MAbs) were produced to secretions and to whole Heterodera avenue 2nd-stage juveniles; several of these MAbs recognized molecules present in nematode secretions produced in vitro. Three of these molecules have been partly characterized in H. avenae, Globodera rostochiensis, G. pallida and Meloidogyne incognita. A MAb reacting with the surfaces of these nematodes recognized antigens of different molecular weight in each of the species tested. This difference in antigenicity might be related to specific functions in these nematodes. Preliminary results show that this antibody also localized the antigen in root cells surrounding the feeding site induced by M. incognita in Arabidopsis thaliana.
Amelioration of murine cerebral malaria by dietary restriction
Authors: Hunt N. H. , Manduci N. , Thumwood C. M.
Published: June 2009

CBA/T6 strain mice infected withPlasmodium bergheiANKA develop cerebral symptoms and die, with mononuclear cell attachment to the cerebral microvascular endothelium, petechial haemorrhages and breakdown of the blood–brain barrier, some 6–7 days post-inoculation. The effects of dietary restriction on this process were examined. Mice were fedab libitum(Group 1) or their food was restricted to produce body weight loss of 1·0–2·0 % (Group 2), 2·5–3·5 % (Group 3), 4·0–6·5 % (Group 4) or 7·0–9·5 % (Group 5) relative to Group 1. Dietary restriction reduced deaths caused by cerebral malaria from 100% in Group 1 to 47% (Group 2), 43% (Group 3), 10% (Group 4) and 53% (Group 5). Restriction of food intake had no effect on (1) the progression of parasitaemia in infected mice (2) changes in haematocrit, spleen weight, total lymph node cell number or (3) peritoneal exudate cell number in either malaria-infected or uninfected mice.P. bergheiANKA infection did not significantly affect the proportion of lymph node leucocytes that were Thy-1+T cells or CD8+T cells, but did lead to significant increases in the CD4+and B cell populations. Dietary restriction alone increased the lymph node CD4+cell population but did not affect the increase in B cells in malaria-infected mice.P. bergheiANKA infection and dietary restriction together did not lead to increased CD4+cell numbers in lymph node leucocytes. Thein vitroproliferative response of isolated lymph node cells to concanavalin A or phorbol myristate acetate plus ionomycin was measured and found to be identical in all treatment groups. Plasma levels of tumour necrosis factor (TNF) increased from undetectable in uninfected mice orP. bergheiANKA-infected mice on days 1–6 post-inoculation to 21 ± 2 ng/ml on day 7 when cerebral symptoms were at their height and death was imminent. This increase in plasma TNF was substantially inhibited in those mice subjected to regimes of dietary restriction. There was a good correlation (r2= 0·73) between plasma TNF level and percentage mortality in the 5 treatment groups. The results indicate that dietary status is an important factor in the outcome of murine cerebral malaria and perhaps, by extrapolation, in the human disease.
The control of trichostrongyle larvae (Nematoda) by fumigation in relation to their bionomics
Authors: Sturrock R. F.
Published: June 2009

Laboratory experiments indicated that third-stage larvae of T. axei and T colubriformis were able to penetrate soil to a depth of 12 in. or more, although most larvae remained in the upper 2 in. No geotaxis was observed.

Heavy downflows of water caused severe mortalities but did not affect the rate of movement of surviving larvae through the soil. Very limited random lateral movement occurred in turf, being more pronounced in the presence of faeces. Prolonged desiccation was extremely lethal to infective larvae. The activity of larvae was directly and linearly proportional to normal temperatures. The average activity of groups of larvae declined with time.

The author wishes to acknowledge the assistance and facilities provided by Professor B. G. Peters and the other members of staff of Imperial College Field Station, and to thank Dr C. W. R. Spedding for helpful criticism and supplying culture lambs; and Dr T. E. Gibson and Dr P. Silverman for supplying pure cultures of trichostrongyle larvae.
Spermatogenesis in the hermaphroditic Digenea (Trematoda)
Authors: Gresson R. A. R.
Published: June 2009

While some variation of detail may be found in different species of the hermaphroditic Digenea, the process of spermatogenesis conforms to a common plan throughout the group. There is divergence of opinion concerning the interpretation of the structure of the ripe spermatozoon.

In the testis of a young animal, primary, secondary and tertiary spermatogonia are present. The tertiary spermatogonia divide to give a group of eight primary spermatocytes that undergo the first division of the meiotic phase to form sixteen secondary spermatocytes. As a result of the second division of the meiotic phase, the sixteen secondary spermatocytes give a group of thirty-two spermatids that through a complicated series of changes are transformed into spermatozoa. During spermateleosis much of the cytoplasm of the late spermatid is sloughed off.

Recent research, including the application of the Feulgen technique, the examination of living material, and electron microscopy, supports the view that the ripe spermatozoon is composed of an elongate head, and a flagellum. The head, with the exception of its external sheaths, consists of nuclear material.

The flagellum of the sperm of Fasciola hepatica is Feulgen-negative and is composed of a proximal and a distal region. Its proximal part is provided with two axial filaments, a middle fibril and an external sheath. The axial filaments and the middle fibril are continued into the distal region where the external sheath appears to be absent. The external sheath of the flagellum of the sperm of Haematoloechus ( = Ostiolum) medioplexus is said to be composed of thirty-six fibrils. Claims that the flagellum of some digeneans contains a centriole, a middle-piece, and mitochondria have not so far been substantiated by means of electron microscopy.
Role of adult worms in immunity of rats to Nippostrongylus brasiliensis
Authors: Ogilvie Bridget M.
Published: June 2009

Immunity to N. brasiliensis in rats is stimulated primarily by the adult worms. An initial infection consisting solely of adult worms terminated at the same time as an infection consisting of all the parasitic stages.

Immunity is not stage specific. Immunity stimulated by adult worms acts not only on adult stages inhibiting their reproduction but also inhibits the development to maturity of larvae in a challenge infection.

Rats infected solely with female adult worms, whether egg producing or sterile, are more resistant to reinfection than rats infected with male worms only.

Immunity stimulated by a single normal infection lasts a long time but it does not depend on the persistence of adult worms in the intestine of the rats.

This work was done during the tenure of a Commonwealth Scholarship awarded by the Association of Commonwealth Universities.
Some experiments on the nutrition of Moniliformis dubius Meyer (Acanthocephala)
Authors: Edmonds S. J.
Published: June 2009

When rats infected with Moniliformis dubius were dosed orally with labelled sodium phosphate considerable quantities of 32P were found to have been absorbed by the gut-mucosa of the rats and the tissues of the parasites. When the rats were dosed intraperitoneally considerable quantities of 32P were found in the gut-mucosa of the rats but only small quantities in the tissues of the parasites. Similar results were obtained when the experiment was repeated using labelled L-leucine 14C in place of the phosphate and estimating 14C in place of 32P.

The available evidence indicates that M. dubius depends for some of its food-requirements on the contents of the gut of its host rather than on the tissues of its host.

Preliminary experiments showed that the rate of uptake of L-leucine 14C by M. dubius in vitro was decreased if one of the following amino acids were present: DL-valine, DL-serine or DL-methionine.

The author wishes to thank the Department of Biochemistry of the University of Adelaide for the assistance given to him with the experiments on the estimation of 14C.
The effects of thiouracil and thyroxine on the host-parasite relationship of Amplicaecum robertsi Sprent & Mines, 1960, in the mouse
Authors: Dobson Colin
Published: June 2009

When infected with equal numbers of eggs of Amplicaecum robertsi normal male mice harboured more larvae than normal females. Treatment of the mice with thiouracil and thyroxine eliminated the differences between the sizes of the worm populations shown between the sexes in normal mice.

Thiouracil treatment increased the susceptibility of mice to A. robertsi infection, but caused a stunting of the larvae. Thyroxine treatment had no effect on the host–parasite relationship.

It is suggested that the differential ability of the larvae to hatch, penetrate the tissues of the host and migrate to the liver in thiouracil- and thyroxine-treated mice was responsible for the differences in the sizes of the larval populations observed.

This investigation was carried out during the tenure of a Senior Research Fellowship from the Wool Research Board of Australia. I should like to thank Professor J. F. A. Sprent for his continued interest and Mr C. Wilkinson for his careful assistance.
The structure and function of the adhesive organ in strigeid trematodes
Authors: Öhman Christina
Published: June 2009

The biology and life-cycle of Holostephanus lühei is briefly described. The similarities in morphology between the adhesive organ gland cells of H. lühei and Cyathocotyle bushiensis are stressed. Alkaline and acid phosphatases were demonstrated in the adhesive organ gland cells and cuticle. Acid phosphatase also occurs in the caecal cells. Non-specific esterase, sensitive to E600 10−5M and Mipafox 10−3M, is present in the gland cells. The caeca contain a non-specific esterase sensitive to AgNO3 10−2M and PCMB 10−4M. Leucine aminopeptidase is present in the gland cells. The in vitro studies confirmed that the secretory products pass to the exterior of the parasite and have a histolytic action.

The four strigeids studied, Cyathocotyle bushiensis, Holostephanus lühei, Diplostomum spathaceum and Apatemon gracilis minor, are compared and the biological role of the secreted enzymes are discussed.

My sincere thanks are due to Dr D. A. Erasmus for suggesting this line of investigation and for his encouragement during the study. I am also grateful for his performing, on my behalf, the infection experiments and criticizing the manuscript. I wish to thank Professor J. Brough for his interest in the progress of the work, and the University College, Cardiff, for a grant from William E. Morgan's Bequest.
The development of Eimeria necatrix Johnson, 1930 and Eimeria brunetti Levine, 1942 in the caeca of the domestic fowl (Gallus domesticus)
Authors: Horton-Smith C. , Long P. L.
Published: June 2009

When sporozoites of E. necatrix or E. brunetti are injected into the caeca of coccidia-free chickens they penetrate the caecal epithelium and initiate life-cycles which are similar to those developing in the usual sites in the small intestine. Viable oocysts of E. necatrix are produced which can be sporulated and, when given to coccidia-free chickens, produce characteristic infections in the small intestine. Possible implications of this investigation are discussed.
A new species of Angiostrongylus in an Australian rat, Rattus fuscipes
Authors: Bhaibulaya Manoon
Published: June 2009

A survey of lungworm infection in rats in Queensland has shown that 23% of Rattus norvegicus, 6·5% of R. rattus 4·5% of R. fuscipes and 0% of Melomys cervinipes were infected with lungworms. Detailed examination of the lungworms revealed that there are two distinct species; one is Angiostrongylus cantonensis which was found to occur in R. norvegicus and R. rattus, the other is a new species, namely, A. mackerrasae, which was found in R. fuscipes in an area of rainforest near Brisbane. Some R. norvegicus in Brisbane also harboured A. mackerrasae. The two species were distinguished by the length of the spicules, relative length and appearance of the postero-lateral ray in the male, the presence of a minute projection at the tip of the tail in the female, length of the vagina and the distance between anus and vulva. The first-stage larvae of the two species were found to be identical. As this species has been found to be the only lungworm in R. fuscipes which is an indigenous Australian rat, it is suggested that A. mackerrasae may have originated in the Australian region.

I wish to express my sincere gratitude to Professor J. F. A. Sprent and Dr L. R. Ash for their advice and encouragement during this study. Special thanks are also due to Miss M. Cremin for her assistance and to Mr H. Lavery for providing specimens from North Queensland. This work was supported by a grant from the U.S. Department of Health, Education and Welfare No. A 107023–02.
The effect of ageing on the metabolism of the infective larvae of Strongyloides ratti Sandground, 1925
Authors: Barrett J.
Published: June 2009

The infective larvae of S. ratti had a high Qo2 (9·8 μl/mg dry weight/h at 20 °C). Their R.Q. was 0·74 indicating that lipid was the main metabolite.

As the infective larvae aged there was an exponential decrease in their infectivity and a corresponding decrease with age in the Qo2 rate of activity and rate of substrate utilization. The R.Q. of fresh and aged larvae was the same showing that there was no change in the substrate being utilized.

The infective larvae of S. ratti contained 25% lipid 3% glycogen and 0·25% free sugars (dry weight). The free sugars consisted of glucose and trehalose in approximately equal amounts. Both lipid and glycogen decreased as the larvae aged.

Analyses showed all the normal lipid components to be present, the major lipid fraction detected was free fatty acid. As the larvae aged there was a big decrease in the amounts of triglyceride and free fatty acid. There was, however, no difference in the amounts of cholesterol or in the phospholipid composition of fresh and aged larvae.

The fatty-acid composition of the larvae was analysed; 68% of the total fatty acids were unsaturated and the major fatty acid was C18:1. As the larvae aged, the fatty acids were not all catabolized at the same rate; the acid C18:1 was the most heavily catabolized decreasing by 75% in 8 days, whilst C20:1 decreased by only half this amount in the same time.

The distribution of lipid and glycogen was investigated histochemically. Lipid droplets were confined to the posterior two-thirds of the infective larvae and occurred in the lateral lines, non-contractile parts of the muscles and in the cells of the intestine. As the larvae aged the lipid in the body wall and lateral lines disappeared first. Dark granules, possibly excretory products, accumulated in old larvae. Glycogen was found in the lateral lines throughout the length of the larva.

I should like to thank Dr P. Tate for his constant advice and encouragement. This work was carried out during the tenure of a Medical Research Council scholarship.
On the environment ofPolymorphus minutus(Acanthocephala) in ducks
Authors: Crompton D. W. T.
Published: June 2009

Crompton & Harrison (1965) complied from the literature a list of 84 species of bird which have been reported to be final hosts ofPolymorphus minutusand since then, the parasite has been found in the American White-winged Scoter (Melanitta deglandi) and the Chestnut Teal (Anas castanea) by Schmidt (1965) and Avery (1966) respectively. Unless detailed investigations are undertaken, there is no way of knowing how many of these birds from true hosts in whichP. minutuscan reproduce successfully.P. minutushas also been reported from the muskrats (Ondata zibethica) which Golvan (1961) considered to be an accidental host and I have recovered seven living specimens ofP. minutus48 h after forcibly feeding 20 cystacanths of the parasite contained inGammarus pulexto a female Wistar rat. The seven worms were firmly attached to the rat's intestinal wall and all were located in the posterior half of the intestine.
Sarcocystis of rodents and marsupials in Brazil
Authors: Shaw J. J. , Lainson R.
Published: June 2009

Sarcocystis species have been described in a wide variety of mammals, birds and reptiles throughout temperate and tropical countries of the world. Although early workers (Alexeieff, 1913; Wenyon, 1926) considered it impossible to differentiate species on the morphology, there are such clear-cut differences in the structure of the cyst wall, morphology of spores and other details, that there at present seems every justification for giving specific rank to these different parasites in their various hosts. Furthermore, with one or two exceptions, attempts to infect laboratory animals have met with little or no success and it would appear that at least some species of Sarcocystis may be highly host-specific.
Studies of the amino acids of Rhodnius prolixus. I. Analysis of the haemolymph
Authors: Harington J. S.
Published: June 2009

1. A qualitative and semi-quantitative analysis of the free amino acids in the haemolymph of Rhodnius prolixus has been made by paper chromatography.

2. Twenty-one amino acids or related compounds were detected of which histidine appears at the highest concentration.

3. The α-amino-N concentration of haemolymph is among the lowest values recorded for insect haemolymphs.

4. A substance corresponding in position to thyroxine has been detected in haemolymph of a few immature insects, and is formed if iodate is added to freshly withdrawn haemolymph.

I wish to record my great appreciation to the late Professor P. A. Buxton, C.M.G., F.R.S., for his valuable assistance and criticism during this study and to members of the staff for helpful discussions. The study forms part of a Thesis for the degree of Ph.D. approved by the University of London, and was financed by the South African Council for Scientific and Industrial Research whose generous support I acknowledge with pleasure.
Studies on Trypanosoma avium
Authors: Baker J. R.
Published: June 2009

A strain of Trypanosoma avium isolated from Corvus frugilegus in England was readily cultivated in vitro in diphasic blood agar, or blood nutrient agar, media at 28 °C.

In both media, small trypanosomes appeared which morphologically resembled the metacyclic forms from the insect vector and which were infective to canaries. They were more numerous, and developed more regularly, in the medium with the nutrient agar base.

At 40–41 °C a few of these small trypanosomes apparently developed into large trypanosomes similar to, but not identical with, those seen in the blood of infected birds.
An electron microscope study of the body wall of the third-stage larva of Nippostrongylus brasiliensis
Authors: Lee D. L.
Published: June 2009

The cuticle of the third-stage larva of Nippostrongylus brasiliensis consists of seven layers: an outer triple-layered membrane, a double-layered outer cortex, an inner cortex, a matrix layer, a striated layer and two fibril layers. In each ‘annule’ two fibres run transversely around the nematode and lie between the inner cortex and the matrix layer. There is no basement lamella.

The hypodermis is a thin layer between the muscles and the cuticle, but expands to form the dorsal, ventral and lateral cords. The nerves lie between the plasma membrane of the hypodermis and the basement membrane or between the plasma membrane of the hypodermis and the sarcolemma of the muscles. The muscle cells are typical of those described previously for nematodes. The ‘myofibrils’ are apparently similar to those of Ascaris.

An excretory canal is present in each lateral cord and is enclosed by the basement membrane but is not embedded in the hypodermal tissue. Numerous small vesicles appear to move across the wall of the excretory canal and open into the central lumen.

I am grateful to Dr P. Tate, Dr R. W. Horne and Dr K. A. Wright for helpful discussions, to Professor C. P. Read and Dr A. Enders for the use of facilities at Rice University, Houston, Texas and to Professor J. D. Boyd for permission to use the electron microscope in the Department of Anatomy. Thanks are also due to Mr A. J. Page for technical assistance.