bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasmodium knowlesi in the marmoset (Callithrix jacchus)
Authors: Langhorne J. , Cohen S. 
Published: June 2009

SUMMARYCommon marmosets were shown to be susceptible to Plasmodium knowlesi malaria. The morphology of the parasite was indistinguishable from that observed in the natural host (Macaca fascicularis) and the common laboratory model (Macaca mulatta). A differential susceptibility to P. knowlesi was observed in the 8 marmosets studied. Multiplication rates of parasites were variable over 24 h periods. Five animals died of a fulminating infection within 12–17 days after challenge. Three animals recovered spontaneously from infection and were subsequently resistant to challenge with homologous and heterologous variants and strains of P. knowlesi. This resistance was maintained for intervals up to 100 days between challenge infections.
Aldose reductase and sorbitol dehydrogenase in the muscle ofAscaris suum(Nematoda)
Authors: Goil M. M. , Harpur R. P. 
Published: June 2009

SummaryThe muscle ofAscaris suumcontains sorbitol dehydrogenase [EC 1.1.1. 14] and the apparentKmvalues indicate that the enzymefavours fructose formation. Aldose reductase [EC 1.1.1.21] is also present and like the mammalian enzyme it has a very high apparentKmfor glucose. Possible functions of the sorbitol pathway inAscarismuscle are discussed.
Further observations on immunization of sheep against Schistosoma mansoni and S. bovis using irradiation -attenuated schistosomula of homologous and heterologous species
Authors: Bickle Q. D. , Taylor M. G. , James E. R. , Nelson G. S. , Hussein M. F. , Andrews B. J. , Dobinson A. R. , Marshall T. F. de C. 
Published: June 2009

SUMMARYThis paper describes further characteristics of the immunization of sheep against schistosomes using live, irradiated schistosomula. Sheep immunized with a non-virulent strain of Schistosoma mattheei were protected against a more virulent strain of the same species for over a year. As there was no evidence that the irradiated parasites were able to persist this long, it was concluded that the vaccine had induced a sterile resistance. Heterologous vaccination, using irradiated S. mattheei schistosomula to immunize against S. bovis or irradiated S. mansoni schistosomula to immunize against S. mattheei, failed to induce any protection.
Ultrastructural immunocytochemical localization of two hydatid fluid antigens (antigen 5 and antigen B) in the brood capsules and protoscoleces of ovine and equine Echinococcus granulosus and E. multilocularis
Authors: Davies Caroline , Rickard M. D. , Bout D. T. , Smyth J. P. 
Published: June 2009

SummaryThe unlabelled antibody method was used in the ultrastructural localization of two hydatid fluid antigens, antigen 5 and antigen B, in brood capsules and protoscoleces of Echinococcus granulosus and E. multilocularis. Antigen 5 was found in the parenchyma cells of the protoscolex and brood capsule wall and to a lesser extent in the walls of the flame cells and collecting ducts of the excretory system and in the surrounding interstitial material. It is suggested that, while some excretion of this antigen may occur from the protoscolex, it could also be liberated into the cystic cavity by degeneration of protoscoleces and parenchymal cells of the brood capsule wall. Antigen B was found mainly in the distal cytoplasm and perinuclear cytoplasm of the tegument anterior to the suckers. It is apparently secreted to the outside and was present in the brood capsule contents; it adheres to the anterior surface and the posterior periodic acid–Schiff (PAS)-positive glycocalyx of the protoscolex and to the inner surface of the brood capsule wall. The protoscolex tegument posterior to the suckers was negative. The parenchyma cells of the protoscolex and brood capsule wall were also positive although the intensity of the reaction product was variable.
Schistosoma mansoni from naturally infected Rattus rattus in Guadeloupe: identification, prevalence and enzyme polymorphism
Authors: Rollinson D. , Imbert-Establet Danièle , Ross G. C. 
Published: June 2009

SUMMARYAn enzymatic comparison has been made between isolates of Schistosoma mansoni from rats and humans in Guadeloupe and a Burundi isolate of S. rodhaini. Analyses of LDH, MDH, AcP, PGM, GPI, G6PDH and HK by isoelectric focusing provided no evidence for the involvement of S. rodhaini in the recent evolution of the schistosomes currently endemic in Guadeloupe. No distinction could be made between murine and human isolates of S. mansoni and it is suggested that murine schistosomiasis should not therefore be ignored in control programmes. Rattus rattus were captured at seven sites around the island; of 142 examined, 48 were positive for schistosomes. Differences in prevalence between habitats were marked and only small changes in prevalence were observed in localities sampled in 1982 and 1983. Animals with the greatest worm burdens were associated with areas of high prevalence, and age-related changes in worm burden were observed. Two alleles, a and b, at the MDH-1 locus of S. mansoni from rats were identified. Differences in the overall frequencies of these alleles were observed for schistosomes from different localities. Allelic frequences representative of schistosomes from rats at four localities were stable from 1982 to 1983. The majority of positive animals, even those with light worm burdens, were found to be infected with a number of different schistosome genotypes.
Lipid metabolism in golden hamsters infected with plerocercoids ofSpirometra erinacei(Cestoda: Pseudophyllidea)
Authors: Tsuboi T. , Hirai K. 
Published: June 2009

SUMMARYGolden hamsters infected withSpirometra erinaceiplerocercoids develop a hypertriglyceridaemia characterized by an increase in very low-density lipoprotein. Acyl-CoA synthetase activity, the rate of fatty acid synthesis in the liver and triglyceride production studies showed that the activation and synthesis of fatty acid and production of triglyceride in plerocercoidinfected hamsters were not significantly different from the controls. Lipase activity in post-heparin plasma was found to be suppressed in plerocercoid-infected golden hamsters. The presence of plerocercoids also resulted in a significant reduction in serum thyroxine, but the hypertriglyceridaemia associated with plerocercoid infection was not reversed by injecting the infected hamsters with 2 μg/ day doses of L-thyroxine. The levels of serum immunoreactive insulin in plerocercoid-infected hamsters were not significantly different from the controls. We conclude that the hypertriglyceridaemia, associated with plerocercoid infection in hamsters, results predominantly from a suppression of triglyceride degradation, and that the suppression of lipase activity is probably not the result of hypothyroidism or the lack of insulin, but the result of secretion of growth hormone-like substances.
Serial passage of Eimeria tenella and E. necatrix in turkey embryos
Authors: Kogut M. H. , Gore T. C. , Long P. L. 
Published: June 2009

SUMMARYThe serial passage of 3 strains of Eimeria from the chicken in embryonating turkey embryos is reported here. All 3 strains increased their reproduction in turkey embryos; reproduction being equal to or better than the same lines maintained in chicken embryos. Pathogenicity and immunogenicity trials conducted in chickens using these 3 strains of Eimeria showed that all 3 turkey embryo-adapted lines were significantly less pathogenic than the parent lines. Only 1 of the lines (E. tenella (PS) turkey embryo-adapted) maintained its immunogenic potential
Ultrastructural observations on oogenesis and shell formation in Gyrinicola batrachiensis (Walton, 1929) (Nematoda: Oxyurida)
Authors: Adamson M. L. 
Published: June 2009

SUMMARYIndividual females of Gyrinicola batrachiensis produce 2 types of eggs: thin-shelled auto-infective eggs are produced in the ventral horn of the reproductive tract and thick-shelled eggs (transmission agents) are produced in the dorsal horn. Fine structure of oogenesis and egg-shell formation in the 2 horns of the reproductive tract were studied and compared. Early stages of oogenesis were similar in both horns but mature oocytes differed considerably. Those in the dorsal horn were larger than those in the ventral horn; they contained large numbers of lipid droplets, peripheral patches of glycogen and several types of cytoplasmic granules presumably acting as yolk or playing a role in shell formation. Mature oocytes in the ventral horn contained large amounts of glycogen, relatively few lipid droplets and large multivesicular bodies. Four shell layers formed around ova in the dorsal horn: a vitelline layer, a lipid layer, a chitinous layer and an outer protein coat similar to that described in other oxyurids. Only the vitelline layer formed around thin-shelled eggs. Thick-shelled eggs did not embryonate in utero but thin-shelled eggs nearest the vagina contained larvae. The first moult in eggs of G. batrachiensis was described in a previous communication and it is suggested here that the thin fibrous layer loosely applied to the cuticle of infective larvae in thin-shelled eggs is the moulted 2nd-stage cuticle.
Two new species of Lepeophtheirus (Copepoda: Caligidae) parasitic on fishes from southern California waters
Authors: Dojiri Masahiro 
Published: June 2009

SUMMARYTwo new species of Lepeophtheirus are described and illustrated based on a collection from the Orange County sewer outfall, California. They are: L. remiopsis sp.nov. from the branchial cavities and external body surfaces of Parophrys vetulus Girard, Hippoglossina stomata Eigenmann & Eigenmann, Pleuronichthys verticalis (Jordan & Gilbert), Chitonotus pugetensis (Steindachner), and Porichthys notatus (Girard); and L. rotundipes sp.nov. from the external body surfaces and occasionally the gill cavities of Scorpaena guttata (Girard) and Citharichthys stigmaeus Jordan & Gilbert.
Bovine trypanosomiasis: the red cell kinetics of Ndama and Zebu cattle infected withTrypanosoma congolense
Authors: Dargie J. D. , Murray P. K. , Murray Max , Grimshaw W. R. T. , McIntyre W. I. M. 
Published: June 2009

SUMMARYThe responses of susceptible Ndama and Zebu cattle to needle challenge withTrypanosoma congolensewere followed using parasitological, haematological and radio-isotopic methods and compared with those of corresponding uninfected animals. In both breeds, infection became patent at the same time but peak parasitaemias were significantly lower, were attained later and were of short duration in the Ndama. All infected animals became anaemic, the severity of which correlated with the level and duration of parasitaemia. However, even when parasites could no longer be detected in the blood, packed cell volumes showed little tendency to recover. The anaemia was due to increased intravascular red cell destruction and was more pronounced in the Zebu. Haemodilution was not a feature. Increased red cell synthesis occurred in infected animals of both breeds but particularly in the Zebu; this accounted for the capacity to maintain packed cell volume levels following the initial drop associated with parasitaemia. However, in most cases red cell synthesis was less than expected from the degree of anaemia, suggesting impairment of bone marrow function. Measurement of red cell iron utilization indicated that this was due to defective iron re-utilization from degraded red cells arising from reticulo-endothelial blockade. It is concluded that the anaemia in this disease and its underlying processes are broadly in line with the number of parasites in the blood and that the superior resistance of the Ndama cattle lies in their ability to control parasitaemia rather than their capacity to mount a more efficient erythropoietic response.
In vitrovariation of glycogen content in three sheep nematodes
Authors: Premvati G. , Chopra Ashok K. 
Published: June 2009

SUMMARYIn vitrovariation of glycogen content under aerobic conditions was measured on fresh weight basis in 3 sheep nematodes inhabiting different niches;Haemonchus contortus, Oesophagostomum columbianumandTrichuris ovis. The parasites were separated into species and then sexes and starved for varying periods of time up to 24 h in glucose-free physiological saline. The differences between females and males and among the species with respect to glycogen content and its rate of change with time are discussed.
Evidence for genetic diversity in Trypanosoma (Nannomonas) congolense
Authors: Majiva P. A. O. , Hamers R. , Van Meirvenne N. , Matthyssens G. 
Published: June 2009

SUMMARYGenetic proximity between two karyotypic groups of Trypanosoma congolense was investigated using as hybridization probes: (i) total genomic DNA, (ii) a 35 nucleotide long synthetic oligonucleotide, and (iii) non-variant antigen type (non-VAT) specific complementary DNAs. The phylogenetic relationship between Trypanosoma brucei and T. evansi, both of which are accepted species in the subgenus Trypanozoon, was used as a reference to assess the phylogenetic proximity of the two groups of T. congolense. Results indicate that some morphologically indistinguishable T. congolense populations differ in a variety of molecular and genetic properties: molecular karyotypes, majority of the DNA sequences, and the restriction enzyme sites in the genomic environments of various conserved genes. The implications of these findings for trypanosome evolution and T. congolense epidemiology are discussed.
Identification of non-cross-reacting antigens ofOnchocerca volvuluswith lymphatic filariasis serum pools
Authors: Lobos E. , Weiss N. 
Published: June 2009

SUMMARYOnchocerca volvulusproteins labelled with125I were immunoprecipitated with onchocerciasis and lymphatic filariasis human serum pools in order to differentiate between cross-reacting and non-cross-reacting antigens. Analysis of the immunoprecipitates by two-dimensional gel electrophoresis revealed that all high molecular weight (Mr)O. volvulusantigens cross-reacted with the lymphatic filariasis serum pools. We observed, however, that at least 80. volvulusantigens were specifically immunoprecipitated only by the onchocerciasis serum pools, with Mrranging from 20000 up to 43000 Daltons. These results suggest that the lower MrO. volvulusantigens are more species specific than the other antigens. The significance of these findings for the immunodiagnosis of onchocerciasis is discussed.
Gametocytogenesis of Plasmodium falciparum in vitro: an electron microscopic study
Authors: Sinden R. E. 
Published: June 2009

SUMMARYPlasmodium falciparum was grown in vitro in blood taken from naturally infected Gambian patients, and the development of the cultured sexual parasites was studied by light and electron microscopy. The young (Stage II and III) female gametocytes undergo a single cryptomitotic nuclear division. This division immediately follows the S phase which Sinden & Smalley (1979) have demonstrated in the Stage I and II gametocytes of both sexes. The male gametocytes, by contrast, do not undergo mitosis during their maturation period in the erythrocyte and thus remain polyploid. Hence the cell cycles of the male and female gametocytes differ significantly. The ultrastructural basis of the characteristic changes in shape of the developing gametocyte are shown to be due to the assembly and subsequent loss of components of the sub-pellicular membranous and microtubular cytoskeleton. Stage I–III gametocytes synthesize numerous ribosomes and endoplasmic reticulum. This correlates with the active synthesis of RNA and protein in these young parasites (Sinden & Smalley, 1979). The marked reduction in macromolecular synthesis in the mature parasites is paralleled by a reduction in cytoplasmic ribosome density in the male gametocyte only. In the female, however, this reduction in activity is correlated with the appearance of a nucleolus. These changes suggest that different mechanisms are being used to control RNA synthesis in the two sexes of gametocyte.
Studies on the relationship between the survival of Schistosoma mansoni larvae in mice and the degree of resistance produced
Authors: Bickle Q. D. 
Published: June 2009

SUMMARYThese studies were aimed at giving a clearer idea of the source of the antigens responsible for the induction of resistance by larval schistosomes. Firstly, the resistance induced by radiation-attenuated (20 krad.) infections was compared with that induced by the larval phase of unirradiated infections. The superiority of the irradiated larvae was demonstrated by infecting mice with 500 female cercariae which were either unirradiated or irradiated, and challenging them 3 weeks later with male cercariae. At perfusion, when primary and challenge worms could be distinguished by sex, significantly greater resistance was demonstrated in the groups vaccinated with irradiated larvae (56 cf. 31% and 48 cf. 26% in two experiments). Secondly, in order to establish how long immunizing larvae need to survive to stimulate optimum resistance, mice were either treated with schistosomulicidal drugs or had the site of infection excised at various intervals post-vaccination. Treatment or excision at up to 24 h did not result in significant resistance to challenge (6–16%). Similar treatments at 1 week did not prevent significant resistance developing (26–37%) but the levels of resistance were significantly lower than those manifest by vaccinated, untreated mice (51–71%). It is concluded that the immunizing larvae need to persist for between 1 and 2 weeks in order to stimulate optimum protection and that antigens released during protracted survival and/or death of the larvae in either the skin or the lungs are probably key factors in the induction of resistance.
Prevalence of schistosome infections within molluscan populations: observed patterns and theoretical predictions
Authors: Anderson R. M. , May R. M. 
Published: June 2009

SUMMARYThe paper draws together a large and scattered body of empirical evidence concerning the prevalence of snail infection with schistosome parasites in field situations, the duration of the latent period of infection in snails (and its dependence on temperature), and the mortality rates of infected and uninfected snails in field and laboratory conditions. A review and synthesis of quantitative data on the population biology of schistosome infections within the molluscan host is attempted and observed patterns of infection are compared with predictions of a schistosomiasis model developed by May (1977) which incorporates differential snail mortality (between infected and uninfected snails) and latent periods of infection. It is suggested that the low levels of prevalence within snail populations in endemic areas of schistosomiasis are closely associated with high rates of infected snail mortality and the duration of the latent period of infection within the mollusc. In certain instances, the expected life-span of an infected snail may be less than the duration of the latent period of infection. Such patterns generate very low levels of parasite prevalence. A new age prevalence model for schistosome infections within snail populations is developed and its predictions compared with observed patterns.The implications of this study of observed and predicted patterns of snail infection within molluscan populations are discussed in relation to the overall transmission dynamics of schistosomiasis.
Genetic control of liability to infection with Nematospiroides dubius in mice: direct and correlated responses to selection of mice for faecal parasite egg count
Authors: Brindley P. J. , Dobson C. 
Published: June 2009

SUMMARYMice selected as liable (L) and refractory (R) over 10 generations voided significantly more and less Nematospiroides dubius eggs compared with randomly mated (Rd) mice after primary infection with 100 larvae. Strong positive correlation was found between the numbers of N. dubius eggs in mouse faeces and the numbers of adult N. dubius recovered from mice culled from the R, Rd and L colonies. Selection limit based on a faecal e.p.g. was reached in the L mice after 9 generations whereas the faecal N. dubius e.p.g. voided by the R mice continued to decline throughout selection. In contrast, no change in worm numbers was found in L or R mice after 6 generations. The refractory state of the trait, liability to infection with N. dubius, was inherited as a dominant character with a realized heritability value of ~ 0∣2. Differential correlated responses from N. dubius infectivity compared with N. dubius fecundity and growth indicated murine genetic control of this trait by 2 major genetic units. In general, there were negative phenotypic and genetic correlations between the faecal N. dubius e.p.g. of mice and murine morphological conformation, but positive correlations between the faecal N. dubius e.p.g. of selected mice and establishment, growth and fecundity of N. dubius populations in these mice. There was little correlation between the faecal N. dubius e.p.g. after primary infection and anti-N. dubius antibody titres and parasite female/male sex-ratio.
Endotube–brush border complexes dissected from the intestines of Haemonchus contortus and Ancylostoma caninum
Authors: Munn E. A. , Greenwood C. A. 
Published: June 2009

SUMMARYA procedure for the blunt dissection of the syncytial intestine of Haemonchus contortus to separate the endotube–brush border complex is described. A similar complex can be obtained from the partially cellular intestine of Ancylostoma caninum. The structural features of the complexes from the two sources are compared. The main differences are in the retention of terminal bars by the endotube from A. caninum and in the extent and organization of the microfilaments associated with the basal side of the endotubes.
Effects of parasitization by the insect parasite Hyposoter exiguae on the growth, development and physiology of its host Trichoplusia ni
Authors: Thompson S. N. 
Published: June 2009

SummaryThe weight gain and growth rate of Trichoplusia ni larvae were severely depressed following parasitization by the insect parasite, Hyposoter exiguae. The development of the host was also delayed and juvenile hormone esterase activity present at the normal time of moulting was absent in parasitized insects. Similar effects on growth and development were achieved by rearing host insects on nutrient-deficient media. Accompanying the above effects of parasitization were alterations in dry/wet weight ratio and host haemolymph osmolality. Parasitization resulted in immediate increases in the concentrations of haemolymph non-glycogen carbohydrate (composed of trehalose, maltose and glucose) and protein. The concentration of fat body glycogen also increased following parasitization. In contrast, the concentration of haemolymph non-glycogen carbohydrate and protein, as well as fat body glycogen, decreased in nutrient-deprived larvae. The significance of the above results as they relate to the insect parasite–host relationship is discussed.
An experimental study of the survival characteristics, activity and energy reserves of the hexacanths of Hymenolepis diminuta
Authors: Anderson R. M. , Lethbridge R. C. 
Published: June 2009

Similar survival characteristics were demonstrated for hexacanths of Hymenolepis diminuta incubated in Tyrode's solution with or without a glucose supplement (0–50 mg/ml).The survival rate of hexacanths in all media tested was shown to be age-dependent and led to a maximum life-span of approximately 11 h.The amount of energy reserves, as measured by microdensitometric determinations of PAS + material, declined rapidly in time to a plateau at approximately 8 h. Residual PAS + matter present beyond that period was interpreted as structural and thus non-utilizable material.The rate of activity as measured by hook movements declined more rapidly, and continuous hook cycles were rarely observed after 2 h and ceased after 4 h. A close correlation was demonstrated between the decline in PAS + material and the total number of hook cycles completed per unit of time.The quantitative results on survival, energy reserves and activity are discussed in relation to the penetration of hexacanths into the haemocoele of the intermediate host.