bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunity to coccidiosis: protective effects of transferred serum and cells investigated in chick embryos infected withEimeria tenella
Authors: Elaine Rose M. , Long P. L. 
Published: June 2009

SUMMARYThe chick embryo proved to be an eminently suitable medium for immunological studies onE. tenellainfection, some of the difficulties encountered in the normal host, the hatched chicken, being circumvented.Adoptive transfer of immunity toE. tenellainfections in the chick embryo was obtained with antibodies and with cells from caecal tonsils. Protective factors (antibodies) were demonstrated in the serum of fowls which had been infected withE. tenellaand in their progeny. Suspensions of caecal tosnil cells inoculated on to the CAM of developing chick embryos reduced the extent of subsequent infections withE. tenellaand this was particularly marked when the cell donors had been immunized withE. tenella.Serum globulin protected only when the donors were becoming immune, i.e. after the third inoculum ofE. tenellaoocysts. The experiment was not continued to the point at which the serum donors were ‘solidly immune’, when previous attempts to protect passively with serum have failed.Maternally transmitted protection was demonstrated in embryos only at the time at which peak protection was afforded by serum globulin, but this is probably an unsatisfactory method of testing since antibodies are not present in allantoic fluid until late in incubation, when coccidial infections are already well established.Some reduction in the oocyst output of the progeny of immunized hens was found when these were challenged at 4 days of age.The protection given by the inoculation of suspensions of cells from the caecal tonsils may have resulted from the production of antibodies by these cells or from their interaction with the parasite in some form of cell-mediated immune mechanism.We are grateful to Mrs Patricia Hesketh, Mr Martin Shirley and Mr Ron Waters for technical assistance and to Mr Peter Townsend for care of the animals.
Taenia crassicepssurface immunoglobulins: parasite- or host-derived?
Authors: McManus D. P. , Lamsam S. 
Published: June 2009

SUMMARYIn common with other taeniid cestodes, host or host-like proteins, especially immunoglobulins, occur on the surface and in the cyst fluid ofTaenia crassiceps metacestodes. Here, several approaches have been used to determine the origin of the immunoglobulins present on the tegument. Indirect IFAT showed that IgG was almost totally lost from the surface of bladders after 6 days culturein vitro. There was a rapid reacquisition of immunoglobulins following incubation of the cultured metacestodes with either normal mouse serum or mouse anti-T. crassicepsantiserum. Immunoprecipitation ofin vitrotranslation products and biosynthetically labelledT. crassicepsproteins with a panel of anti-IgG antisera failed to positively identify any molecule with homology to mammalian immunoglobulins. These results suggest strongly that the immunoglobulins located on the surface ofT. crassicepsare of host rather than parasite origin. The occurrence of a relatively low abundance receptor in the surface of the bladders, which binds non-specific host immunoglobulin, together with surface-bound specific anti-T. crassicepsantibodies can account for the presence of these host proteins. Freshly obtained bladders and metacestodes cultured in vitro for 6 days were transplanted into naive mice and the survival and development of the resulting parasites compared. In some individual mice there was a decrease in the number and volume of metacestodes and an increase in encapsulated parasites arising from cultured bladders. This was probably not related to the loss of host immunoglobulins from the parasite surface during culture as the reacquisition of these proteins after transplantation is likely to be far more rapid than any immune response could evoke in a naive host.
The relationship between the frequency distribution of Ascaris lumbricoides and the prevalence and intensity of infection in human communities
Authors: Guyatt H. L. , Bundy D. A. P. , Medley G. F. , Grenfell B. T. 
Published: June 2009

SUMMARYObserved field data from a range of geographically distinct human communities suggest a consistent non-linear relationship between prevalence and mean intensity of Ascaris lumbricoides infection. Utilizing the negative binomial distribution as a description of observed aggregation, maximum-likelihood analysis reveals that the degree of aggregation is a negative linear function of mean worm burden. The factors responsible for this relationship in human populations require further study but may involve some combination of (i) density-dependent reduction in worm numbers within individuals, (ii) density-dependent parasite-induced host mortality or (iii) self-treatment by heavily infected hosts. Variability in the degree of aggregation appears dependent on the level of infection in a community and independent of geographical differences in the host or parasite populations.
Paracrystalline bundles of large tubules, induced in vitro by Mebendazole in Cysticercus cellulosae
Authors: Laclette J. P. , Merchant Marie Therese , Willms Kaethe , Cañedo L. 
Published: June 2009

SUMMARYThe effect of the anthelmintic Mebendazole on Cysticercus cellulosae maintained in culture medium was studied by transmission electron microscopy. In addition to the well-known morphological changes induced by Mebendazole in other cestode and nematode larvae, it also induced the cytoplasmic appearance of paracrystalline bundles in the secretory cells of the bladder wall. These bundles were formed by groups of large parallel tubules arranged in a hexagonal-like pattern. The tubules, which had an external diameter of about 50 nm and a length that might exceed 5 μm, were surrounded by a matrix and a distance between neighbouring tubules of 80–120 nm centre to centre was estimated. The tubules were stable to colchicine and low temperature. The temporary appearance of bundles is described and some alternative explanations on their origin are advanced.
Genetic and immunological characterization of the microsporidianSeptata intestinalisCali, Kotler and Orenstein, 1993: reclassification toEncephalitozoon intestinalis
Authors: Hartskeerl R. A. , Van Gool T. , Schuitema A. R. J. , Didier E. S. , Terpstra W. J. 
Published: June 2009

SUMMARYTh relationships between theEncephalitozoon-likeSeptata intestinalisand other microsporidia that occur in humans, notablyEncephalitozoon cuniculiandEncephalitozoon hellem, is insufficiently documented using morphological descriptions alone. To assess mutual relationships, we have examined other phenotypic as well as genetic aspects ofS. intestinalis, obtained both from tissue culture and clinical specimens, in comparison with a number of other microsporidia. Phenotypic characterization was performed by analysis of the protein composition and antigenic structure of various microsporidian spores by SDS-PAGE and Western blotting. The genetic characterization consisted of the determination of the sequence of theS. intestinalis rrsgene encoding the small subunit ribosomal RNA (srRNA), restriction fragment length polymorphism (RFLP) analysis of amplifiedrrsgenes and establishment of the degree of sequence identity betweenrrsgenes of various microsporidian species. The unique sequence ofrrsofS. intestinalisas well as the distinct RFLP and SDS-PAGE profiles indicate thatS. intestinalisis clearly different from other human microsporidian species. However, itsrrsgene shared about 90% sequence identity withrrsof bothEncephalitozoonspp.,E. cuniculiandE. hellem. This is remarkably higher than the about 70% identity observed betweenrrsof microsporidian species which belong to different genera and thus suggests that S.intestinalisshould be regarded as a species of the genusEncephalitozoon. Western blots revealed a marked cross-reactivity betweenS. intestinalisand both species ofEncephalitozoonwhich also stresses the close relationship between these organisms. It is concluded thatS. intestinalisis so closely related toE. cuniculi, the type species ofEncephalitozoon, that it should be reclassified asEncephalitozoon intestinalis.
Chemical guidance of Onchocerca lienalis microfilariae to the thorax of Simulium vittatum
Authors: Lehmann T. , Cupp S. M. , Cupp W. E. 
Published: June 2009

SUMMARYThe behavioural responses of Onchocerca lienalis microfilariae (mf) to tissue factors of the surrogate black fly host, Simulium vittatum, were studied using a novel in vitro bioassay. Mf accumulated towards thoracic tissues to a density 4 times higher than towards abdominal tissues, despite the larger surface area and volume of abdominal tissues. Mf migrated toward thoracic tissues regardless of whether or not contact with thoracic tissues was possible. Therefore, mf directed themselves toward the thorax rather than arresting their movement after they make contact with thoracic tissues. Chemical cue(s) provided a principal guidance for mf to locate thoracic tissues. Mf lost their ability to differentiate thoracic and abdominal tissues following addition of thoracic attractant(s) to excised abdomens and reversed their differential response when excised thoraces were depleted of chemical cue(s). Mf did not respond to salivary gland product, but to other thoracic factor(s). Intact thorax that was connected to 1–2 abdominal segments attracted considerably less mf than excised thorax. However, intact thorax attracted more mf than excised abdomen. Abdominal tissue size did not affect thorax attractiveness. Involvement of a large molecular weight protein(s) was suggested by the high attractiveness of the 100 kDa Centricon concentrator retentate and complete precipitation of attractant(s) by ethanol.
The influence of the actionmycete,Pasteuria penetrans, on the host–parasite relationship of the plant-parasitic nematode,Meloidogyne javanica
Authors: Bird A. F. 
Published: June 2009

SUMMARYThe actinomycete,Pasteuria penetrans, is a specific endoparasite of various plant-parasitic nematodes. When parasitizing the root-knot nematode (Meloidogyne javanical) the nematode's capacity to reproduce is destroyed and feeding on and stimulation of the plant host are unaffected even though the bulbous body of the female nematode becomes filled with spores. Parasitism by the actinomycete does not alter the rate of growth in the early stages of nematode development although the non-parasitized female grows more rapidly than the parasitized one for a short time immediately after the final moult.Pasteuriadid not invade or inactivate the anterior oesophageal region of the femaleMeloidogyneor influence the morphology of the giant cells induced by these nematodes in their hosts' roots. The influence of this parasite on the developmental physiology of its nematode host is discussed.
The relation between the number of parasites/host and host age: population dynamic causes and maximum likelihood estimation
Authors: Pacala S. W. , Dobson A. P. 
Published: June 2009

SUMMARYWe examined dynamical factors that shape the distribution of the number of parasites/host in constant or temporally varying environments, and with or without host-age dependent variation in host susceptibility and parasite mortality. We predict properties of the parasite distribution in the absence of density-dependent factors such as densitydependent mortality or recruitment and parasite-induced host mortality. These properties provide a criterion for the detection of density dependence in temporally variable systems with host-age dependent interactions. We have then introduced methods to estimate and statistically evaluate the effects of host age or size on the distribution of parasites/host. The methods are based on a maximum likelihood protocol for linear and non-linear regression when data are negatively binomially distributed. We have illustrated the use of the theoretical results and statistical methods by re-analysing the data of Halvorsen & Andersen (1984) on cestode infections in Norwegian arctic charr and by analysing new data on nematode infections in Caribbean Anolis lizards.
Studies on the behaviour of Lucilia illustris Meigen as a parasite of vertebrates under experimental conditions
Authors: Dasgupta B. , roy Pranabesh 
Published: June 2009

When egg-masses of Lucilia illustris, taken from carcasses, were mounted on the body of living vertebrates (Clarius batrachus, Bufo melanostictus, Rana tigrina, Hemidactylus fluviviridis, Columba livia and Suncus murinus), the larvae hatched in the majority of cases under normal conditions of room temperature, and entered into the body of the experimental hosts, ultimately killing them. It appeared that the larvae fed on the brain first before turning their attention to other soft tissues of the hosts. The specimens fed on living tissue had a shorter period of development than those bred on dead animals and the period of development was shortest when the host was a living warm-blooded animal.Thanks are due to Mr H. Oldroyd of the British Museum of Natural History, London, for kindly identifying the fly. The authors also wish to thank Dr T. N. Ghosh of the Calcutta School of Tropical Medicine, who helped with literature; and Dr S. K. Das Gupta, of the Darjeeling Government College, who helped with suggestions at the time of preparing the manuscript.
Sequences in the maturation of the genitalia inTetrabothrius erostris(Loennberg, 1889) from the intestine ofLarus argentatus argentatusPontoppidan
Authors: Rawson Dilys 
Published: June 2009

1. A detailed description, with illustrations, is given, of the sequences in development and maturation of the genitalia inTetrabothrius erostris.This is the first such account of any member of the new order Tetrabothridea.2. The effect of the very marked protandry on the form of the remainder of the genitalia is discussed.3. Attention is drawn to the unusual ovary which produces sclerotin and which it is proposed to call a ‘calycal-ovarium’.4. Comparison is made of the embryophore with that of the Cyclophyllidea. There is a suggestion that the embryophore may be formed of sclerotin inT. erostris.5. Par-uterine vesicles have been described for the first time in any member of the Tetrabothridea. These vesicles arise from the uterine primordium and have previously been confused with testes.6. The complex affinities of the order Tetrabothridea are discussed and some support arises for the creation of this new order.
The susceptibility of fishes to haemoflagellates at different ambient temperatures
Authors: Woo P. T. K. , Wehnert S. D. , Rodgers D. 
Published: June 2009

SummaryTrout acclimated to 20 °C could not be infected withCryptobia salmositica. Those acclimated to 5 °C had longer pre-patent periods and considerably lower parasitaemias than those at 10 °C. Forty days after infection, the parasitaemias in fish at 10 °C fluctuated, while this was not observed in those at 5 °C. In vitro incubation ofCryptobiain plasma from 20 °C fish did not affect the motility nor the infectivity of the parasite. Fish infected at 15 °C (low parasitaemias and 2 weeks after inoculation) lost their infections when the ambient temperature was raised to 20 °C. However, in fish with more acute infections (4 weeks after inoculation), the parasitaemias were only substantially reduced when the ambient temperature was raised to 20 °C.Trypanosoma danilewskyiwere detected in goldfish acclimated to 10, 20 and 30 °C. However, the parasitaemias in goldfish at 10 and 30 °C were consistently much lower than those at 20 °C.
Parasite development and adaptive specialization
Authors: Bianco A. E. , Maizels R. M. 
Published: June 2009

SUMMARYThe complex life-cycles of parasitic animals are a product of exploiting the process of development to generate organisms with different biological potentials within a species. Successive stages of the parasite adapt to functions such as host invasion and transmission, and to the colonization of a variety of niches, often involving different hosts, tissues or cells. Understanding the molecular basis of adaptive biology among parasities is a major challenge that lies at the heart of research in contemporary parasitology. Differences in scale at the levels of genomic complexity and cell biology exist between most parasitic protozoa and helminths, rendering a cautionary note to making generalized observations. The two principal approaches used to gain insights into adaptive specializations are to start with a biological activity and identify the molecule, or select molecules with particular properties and deduce function. Both have their part to play, with their inherent advantages and limitations, and both are illustrated with examples of studies on adaptive biology among parasitic nematodes.
On the egg of the tick, Ixodes ricinus L.
Authors: Arthur D. R. 
Published: June 2009

The egg of Ixodes ricinus L. is described, and the increase in size during development is noted. It is suggested that the increase is due to the absorption of water. The egg wall consists of exo- and endochorion with a thin vitelline membrane, which becomes thicker as development proceeds and assumes a laminated appearance. The secretion layer of Gené's organ is described, and appears to function as a cement for holding the eggs together in the cluster. Chemical tests show it to be of a waxy nature.It is deduced from experimental evidence that the egg shell is not absolutely rigid, and the weight of evidence favours the view that the shape of the egg shell is maintained by the internal pressure of the egg contents, and the elasticity of the shell.The development processes as seen in the living egg are described. Hatching from the egg shell is brought about by a muscular force acting on a limited area at the posterior pole of the egg.The writer is indebted to Mr Robert David, of Longlands Farm, Pyle, Dr A. D. Lees, of the Agricultural Research Council, and Mr Simeon, of the Glamorgan War Agricultural Executive Committee, for supplies of material; to Mr T. W. Tyssul Jones, M.Sc., for his assistance in checking the measurements of the egg dimensions, and to Mr L. Cowley, M.Sc., Assistant Curator (Department of Zoology), National Museum of Wales, and Dr P. Tate, Molteno Institute of Parasitology, Cambridge, for reading the original script and for making many useful suggestions and modifications.
The ecology of the sheep tick,Ixodes ricinusL. Host relationships of the tick: Part 1. Review of previous work in Britain
Authors: Milne A. 
Published: June 2009

On the whole published data on the host relationships ofIxodes ricinusL. in Britain are rather inadequate, but the following points emerge:The tick (stages unspecified) has been found on twenty-three mammal, twenty-one bird and one reptile species. These include both wild and domestic animals. There are no records of non-hosts. The host list is incomplete. Its length and variety suggest, however, that the tick will feed on practically any mammal or bird it may meet.Tick stages found on fifteen mammal, twenty-one bird and one reptile species have been recorded. For a number of reasons (see text) ‘recorded’ absence of any tick stage from an animal is not necessarily reliable. This, together with the incompleteness of the host list, detracts a little from the assertion of several authors, namely, that in general larvae and nymphs occur on both mammals and birds, but adult ticks on mammals only.No precise host-potentials for any wild species relative to sheep (or other important farm stock) have been published in Britain. But, in one area, Scottish mountain hare, red deer and roe deer have been slaughtered on a large scale because of their alleged importance as hosts. Very inadequate data from two authors seem to suggest that as normally stocked populations (a) grouse are negligible compared with sheep as hosts to female ticks, and (b) mountain hare and red deer may play quite an important part in maintaining female ticks. Suggestion (b) at least should not be taken seriously until comprehensively investigated.One author shows that an ‘appreciable’ tick population was maintained on a hill grazing by a reduced wild fauna in the absence of sheep.Another author shows that the tick population of a grazing was considerably reduced by acaricidal treatment of sheep, together with almost complete extermination of a section of the wild fauna. Unfortunately, the two factors cannot be disentangled.We would like to thank Mr Charles Elton, Director, Bureau of Animal Population, Oxford, and Dr J. MacLeod of the Cooper Technical Bureau, Berkhamsted, for criticism of the MS.; Mr F. Wallace for information on red deer stocking; and Dr V. B. Wigglesworth, F.R.S.,. Director, Agricultural Research Council Unit of Insect Physiology, Cambridge, within whose organization the work was done.
Studies in the transmission of Plasmodium malariae by Anopheles mosquitoes
Authors: Shute P. G. , Maryon M. 
Published: June 2009

P. malariae was first used for therapy purposes at Horton in 1928.Between 1928 and 1945, nine strains have been used. Most of these were from Africa, but some were from Holland, Roumania and South America. The strain from Holland was probably not indigenous to that country.All transmission experiments carried out between 1928 and 1945 were with Anopheles maculipennis var. atroparvus. Nineteen separate batches of mosquitoes were fed on patients in whose blood parasites believed to be gametocytes were seen. In only six of these batches were any of the mosquitoes found to be infected and then with only scanty oocysts; sporozoites were never found. No patients were infected by the bites of any of these mosquitoes.In 1947 a colony of A. stephensi (type) was established.From 1948 to 1950, sixty-eight batches of A. stephensi were fed on patients in whose blood Plasmodium malariae parasites were present. Scanty gametocytes were found in some of these patients, and on occasion mosquitoes which fed on them became infected, but in others no infection occurred.Other batches of mosquitoes did become infected after feeding on patients in whose blood no typical gametocytes were found even after a prolonged search. Out of sixty-eight batches of mosquitoes fed, infection was seen in twelve batches, in varying degree, but never with more than nine oocysts in an individual mosquito. Two consecutive human anopheline passages with laboratory-bred Anopheles mosquitoes (A. stephehsi type) and induced human carriers are reported.
Bi-criteria velocity minimization of robot manipulators using LVI-based primal-dual neural network and illustrated via PUMA560 robot arm
Authors: Zhang Yunong , Li Kene 
Published: June 2009

SUMMARYIn this paper, to diminish discontinuity points arising in the infinity-norm velocity minimization scheme, a bi-criteria velocity minimization scheme is presented based on a new neural network solver, i.e., an LVI-based primal-dual neural network. Such a kinematic planning scheme of redundant manipulators can incorporate joint physical limits, such as, joint limits and joint velocity limits simultaneously. Moreover, the presented kinematic planning scheme can be reformulated as a quadratic programming (QP) problem. As a real-time QP solver, the LVI-based primal-dual neural network is developed with a simple piecewise linear structure and high computational efficiency. Computer simulations performed based on a PUMA560 manipulator model are presented to illustrate the validity and advantages of such a bi-criteria velocity minimization neural planning scheme for redundant robot arms.