bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
Observations on the infection of bulinid snails with Schistosoma mattheei
Authors: Kinoti G. K. 
Published: June 2009

In an attempt to determine the mechanisms of resistance to schistosome infection operative in bulinid snails, an histological study was carried out on batches of a refractory strain of Bulinus truncatus and two highly susceptible strains of B. africanus killed at various intervals of time, ranging from 7 h to over 3 months, after exposure to infection with Schistosoma mattheei miracidia.It was found that only a small fraction (less than 1%) of the miracidia penetrated B. truncatus, and that they penetrated only a few of the snails exposed. Much larger proportions (up to 26%) of the miracidia penetrated B. africanus and they penetrated nearly all the snails exposed.In the susceptible B. africanus only miracidia which settled in the loose tissues of the head-foot proceeded to develop: those settling in dense tissue failed to develop and degenerated within about 2 days.A strong infiltration reaction of amoebocytes rapidly destroyed the few miracidia that successfully penetrated B. truncatus. In contrast, B. africanus did not respond to the presence of miracidia in its tissues, nor to mother or to daughter sporocysts before the onset of cercarial shedding: it reacted only to cercariae.It is concluded (a) that the combination of an effective surface barrier and an active defence mechanism due to amoebocytes were responsible for complete resistance to S. mattheei infection in B. truncatus (b) that successful establishment of S. mattheei infection in B. africanus depended on the failure of the snail to recognize the schistosome miracidia and sporocysts as foreign material.I am indebted to Professor George S. Nelson for advice and encouragement in this work which was carried out at the London School of Hygiene and Tropical Medicine. I am most grateful to Dr R. J. Pitchford, Dr C. A. Wright and Dr F. Arfaa for providing material for schistosome and snail cultures and to the East African Community and the British Ministry of Overseas Development for financial support.
Immunity toTrichinella spiralisII. Immunity produced by the adult worm in mice
Authors: Denham D. A. 
Published: June 2009

It has been shown that the 5th or adult stage ofTrichinella spiralisstimulates strong immunity in mice. This was shown using a transfer technique and irradiated worms. A comparison between the immunity produced by a normal infection and one which has been irradiated is made and explanations offered to explain the fact that less immunity is stimulated by irradiated larvae.I would like to express my gratitude to H.M. Treasury and to the Agricultural Research Council for financial support during the time that this work was conducted. I would also like to thank Professor W.I.B. Beveridge, within whose department this work was conducted, for the facilities provided. I would also like to record my gratitude to Dr W. C. Campbell for the many stimulating discussions we have had on the subject ofTrichinella.
The effects of parasitism by the daughter sporocyst ofCercaria bucephalopsis haimaenaLacaze-Duthiers, 1854, on the digestive tubules of the cockle,Cardium eduleL.
Authors: James B. L. , Bowers E. A. 
Published: June 2009

The effects of parasitism by the daughter sporocyst ofCercaria bucephalopsis haimaenaLacaze-Duthiers, 1854, on the digestive cells ofCardium eduleL. was investigated by comparing histochemically stained cells in healthy and parasitized animals. Two effects were apparent: (a) the branches of the daughter sporocysts compress the walls of the digestive gland ducts and tubules, and cut off the more distal tubule cells from their food supply, inducing starvation autolysis, (b) in digestive tubule cells not so cut off, glucose, glycogen, glycoproteins, phospholipid and proteolipid food storage globules and acid mucopolysaccharide are reduced. Neutral lipids, fatty acids, alkaline phosphatase, acid phosphatase and non-specific esterase are increased and there is also a compensatory increase in the number of food vacuoles. In the visceral haemocoel, in the neighbourhood of the parasite, glucose, fatty acids, neutral lipids and acid mucopolysaccharide are increased and glycogen reduced.We are grateful to Professor E. W. Knight-Jones, for helpful comments and good working facilities, and to the Science Research Council, for the grant of a research studentships to one of us (E.A.B.).
The histochemistry of the cystogenous gland cells and cyst wall ofParorchis acanthusNicoll, and some details of the morphology and fine structure of the cercaria
Authors: Rees Gwendolen 
Published: June 2009

The cyst wall ofParorchis acanthusNicoll, consists of an outer wall of three layers and an inner wall of two layers. The outer wall is hemispherical, complete, attached to the substratum and extends as a flange around the margin. The composition of its three layers differ dorsally and ventrally. Dorsally the layers are: (1) acid mucopolysaccharide and neutral mucopolysaccharide, (2) protein and lipoprotein, (3) acid mucopolysaccharide, neutral mucopolysaccharide and glyco-protein. Ventrally the layers are: (1) acid mucopolysaccharide, protein and lipoprotein, (2) acid mucopolysaccharide. The middle layer in both is secreted by the ventral granular cystogenous glands and the outer and inner layers, dorsally and ventrally, by the dorsal and ventral agranular cystogenous glands respectively.The inner cyst wall is oval in surface view. It consists of two layers, both of neutral mucopolysaccharide, the outer giving a more pronounced reaction. Both are secreted by the dorsal granular cystogenous glands. The ventral wall is strengthened by a secretion from the plug-forming gland cells and consists of neutral mucopolysaccharide. All the layers of the cyst wall show the same histochemical reactions as the glands which secrete them.Studies on the fine structure of the cercaria have revealed mammalian-type synapses in the neuropile of the central nervous system, rind cells around the ganglia, an elaborate arrangement of muscles in the wall of the oral sucker, the flame cell structure and the structure of the granules contributing to the formation of the cyst wall.
The morphology and life-cycle of Cephalochlamys namaquensis (Cohn, 1906) (Cestoda: Pseudophyllidea) from Xenopus muelleri and X. laevis
Authors: Thurston June P. 
Published: June 2009

Some morphological characteristics of Cephalochlamys namaquensis from Xenopus muelleri collected at Kajansi, Kampala, are described.Specimens of cestodes from other localities in Africa are compared with those from Kajansi in order to assess the reliability of the characters of the proposed genus Pseudocephalochlamys Yamaguti, 1959. Reasons are given for rejecting the genus.The embryonated, non-operculate egg capsules hatch at once in water. The ciliated coracidium is eaten by cyclopid copepods and the oncosphere rapidly penetrates through the mid-gut wall into the haemocoel. The procercoid develops a cercomer which moves actively during development and which retains the six hooks of the oncosphere. The procercoid develops the scolex, osmoregulatory canals and calcareous corpuscles typical of the adult while within the copepod. It is enclosed within a membrane. The procercoid is infective to Xenopus toads 20 days after being ingested by the copepod. No other intermediate host has been found.Thermocyclops infrequens Kiefer is the intermediate host at Kajansi, Kampala. The maximum number of C. namaquensis recovered from one toad was 103; usually there are between 1 and 6 per toad. Between 22% and 100% of Xenopus muelleri and X. laevis from different localities are infected with C. namaquensis.I wish to express by thanks to the Fisheries Officers and fishermen of Kajansi Fish Farm who have willingly caught Xenopus for me whenever required, and also to the many other people who have assisted me in getting specimens with which to work.I am also indebted to Mr L. Rugema who prepared most of the histological preparations, to Dr J. Green, Westfield College, London, who kindly identified Thermocyclops infrequens, and to Dr G. Rees, University College of Wales, Aberystwyth, who gave me many useful comments during the course of this work.A research grant from Makerere University College contributed towards the cost of obtaining specimens.
Observations on the maintenance of Trichomonas vaginalis and Trichomonas foetus; the effects of cortisone and agar on enhancement of severity of subcutaneous lesions in mice
Authors: Jeffries L. , Harris Margaret 
Published: June 2009

Methods are described for the freezing of trichomonads, suspended in a liverinfusion broth, to – 20 °C and – 70 °C, and storage at these temperatures. After 9 months’ storage at – 70 °C, with dimethyl sulphoxide, six strains of T. vaginalis and three strains of T. foetus were alive; three trichomonas strains frozen earlier were also alive after 13 months. Four of the T. vaginalis strains survived equally well for 6 months at – 70 °C, in the presence of either dimethyl sulphoxide or glycerol.Although trichomonads may be maintained by subculture in a modified Diamond medium, storage at – 70 °C is more economical and less tedious; – 20 °C is not a satisfactory storage temperature for T. vaginalis or T. foetus, even in the presence of dimethyl sulphoxide or glycerol.The severity of subcutaneous lesions in mice produced by six freshly isolated strains of T. vaginalis, and two out of three stock culture strains of T. foetus, was enhanced by either the addition of agar to the suspending medium or administration of cortisone to the mice. One strain of T. foetus produced lesions only in the presence of agar, cortisone, on the dose schedule used, being ineffective.After storage at – 70 °C or cultivation in agar medium for 6 months, the virulence of trichomonads of either species was little affected, and lesions in mice were enhanced by agar in a similar degree to that found originally.For enhancing the severity of subcutaneous lesions in mice the agar method, involving only one injection, is simpler than the repeated administration of cortisone to infected mice; agar was shown to be more effective than cortisone with small infecting doses of one strain of T. vaginalis quantitatively tested.The subcutaneous injection of mice with trichomonads suspended in a liver-infusion broth containing 0·06% agar regularly produces lesions of the degree of severity required for the evaluation of compounds for therapeutic activity.We express our gratitude to Mr S. A. Price for constructive criticism and helpful suggestions during the preparation of the manuscript. Dr S. R. M. Bushby kindly provided details of the dimethyl sulphoxide method and apparatus in use in his laboratory for the low-temperature preservation of tumour cells and trichomonads. For supplying the trichomonas strains we are grateful to Dr L. P. Joyner, Miss M. Moore-Tucker and Mr C. S. Ledwich. We thank Mr W. A. Freeman for advice on the composition of the inoculum medium.
Schistosome vaccines: current progress and future prospects
Authors: Sher A. , James Stephanie L. , Correa-Oliveira R. , Hieny Sara , Pearce E. 
Published: June 2009

SummaryVaccination against human schistosomes in laboratory hosts is now a reality. A number of different parasite molecules have been shown to confer partial protective immunity against challenge infection withSchistosoma mansoniorSchistosoma japonicumin rodent or primate hosts. These antigens are unusually diverse in their structure and stage specificity. Interestingly, although all of the vaccine molecules characterized are situated in the tegument, their exposure on the parasite surface, in most instances, is transient and/or non-essential. The properties of four of these immunogens, glutathione-S-transferase (P26,28), paramyosin (Sm97), GP38, and GP18 are discussed. Despite the identification and recombinant synthesis of several promising protective antigens, vaccination of humans against schistosomiasis remains in the realm of fantasy. At the technical level, a major problem is the failure of any of the current vaccine immunogens and immunization protocols to induce levels of resistance sufficient for significant reduction of human infection or disease. Once this important hurdle is passed, human immunization trials should be attempted as the potential beneficial impact of a vaccine against schistosomiasis remains enormous.
Blood parasites of wild voles,Microtus agrestis, in England
Authors: Baker J. R. , Chitty Dennis , Phipps Ellen 
Published: June 2009

1. Thirty-six of 70Microtus agrestiscaptured near Oxford, England, between January and July, 1961, were infected with blood parasites—9 withTrypanosoma microtiLaveran & Pettit, 1909, 18 withBabesia microtia(França, 1912) and 19 withGrahamella microtiLavier, 1921: some had more than one species.2. Morphologically indistinguishable parasites were found in 6 of 20Clethrionomys glareolus(Babesiain 3,Trypanosomain 2, andGrahamellain 1) and 2 of 4Apodemus sylvaticus(Grahamellaonly).Hepatozoonsp. indet. was found in oneC. glareolus.3. It is probable that the proportion ofM. agrestiswith patent infections ofG. microtiincreased, and possibly that due toT. microtifell, during February–April, 1961.4.M. agrestisoften have very enlarged spleens and it appeared thatB. microtia(sometimes associated withT. microti) was commoner in the animals with the largest spleens.
Two new species of Ardeicola Clay, 1935 (Mallophaga, Ischnocera), from African ibises
Authors: Hajela K. P. , Tandan B. K. 
Published: June 2009

Two new species of Ardeicola Clay, 1925 (Mallophaga, Ischnocera), A. keniensis and A. africanus, ectoparasites of African ibises, Lampribis olivacea akleyorum and L. rara respectively, are described. These species are closely related to each other, and the characters which distinguish them have been enumerated.We are most grateful to Dr Theresa Clay, Department of Entomology, British Museum (Natural History), for the loan of material and for reading the typescript.
The isolation of viable coccidial sporozoites
Authors: Jackson A. R. B. 
Published: June 2009

A method is described by which viable sporozoites of the sheep parasite,Eimeria arloingi, may be obtained in sterile solution and free of any extraneous vegetable matter. Faeces are washed through metal sieves and the oocysts separated by a gravity floatation technique. The oocysts are sterilized and floated free of any remaining faecal debris in a solution of sodium hypochlorite. Sporulation is induced by constant aeration in water. Excystation is effected by incubating firstly under an atmosphere of carbon dioxide and secondly in a solution of trypsin and sheep bile.I wish to thank Professor H. R. Carne for encouragement and advice, and Mr R. F. Jones for skilful technical assistance.
Coccidia in wild populations of the red kangaroo, Megaleia rufa (Desmarest), and the grey kangaroo, Macropus canguru (Müller)
Authors: Mykytowycz R. 
Published: June 2009

The incidence and prevalence of coccidia have been studied in populations of free-living red kangaroos, Megaleia rufa, and grey kangaroos, Macropus canguru, in four geographically distinct areas in Australia.Two new species of Eimeria—E. wilcanniensis and E. toganmainensis—are described from M. rufa, and five—E. cunnamullensis, E. gungahlinensis, E. purchasei, E. kogoni, and E. hestermani—from M. canguru.The incidence of coccidia ranged from 6 to 14% in populations of M. rufa and from 26 to 70% in M. canguru. The susceptibility of the animals to coccidia was analysed in relation to the tibia length. Red kangaroos with tibia approximately 360 mm. long and corresponding to an age of about 12 months were found to be most susceptible. No clinical cases of coccidiosis were seen in the field.Special thanks are due to the owners or managers of the properties on which the kangaroos were sampled; to members of the staff of the Regional Pastoral Laboratory ‘Gilruth Plains’ for their assistance in sampling, and to Messrs E. R. Hesterman, C. Kogon, and D. Purchase, who assisted in the field and the laboratory. Three species of Eimeria have been named after them in acknowledgement of their work. Messrs B. V. Fennessy and J. H. Calaby of this Division kindly read the manuscript.I wish to thank Dr G. B. Sharman for his permission to work with captive kangaroos in Canberra, and Mr E. Slater who took the photographs.
The helminth parasites of some small mammal communities. I. The parasites and their hosts
Authors: Sharpe G. I. 
Published: June 2009

1. A method of trapping small mammals has been described andApodemus sylvaticus, Clethrionomys glareolus, Microtus agrestisandSorex araneuswere captured. The method of trapping has been discussed.2. A survey of the endoparasites found in the four host species has been produced. The two more common hosts and four of their parasites have been chosen for more detailed study.3. The infection levels of the parasites in the two hosts have been calculated and compared with other published data.This work was carried out during the tenure of a Department of Scientific and Industrial Research Studentship. My thanks are due to Dr H. D. Crofton for his very helpful supervision and criticism and to Professor J. E. Harris, F.R.S., in whose department this work was done, for the facilities provided.
The laboratory rearing of Amblyomma sparsum Neumann, 1899
Authors: Walker Jane B. , Parsons B. T. 
Published: June 2009

The successful rearing of Amblyomma sparsum, using rabbits as larval and nymphal hosts and either sheep or tortoise for feeding adults, is described and details of the duration of the various stages are given. The life cycle of this tick is compared with that of A. variegatum and A. nuttalli.The authors are grateful to the Director of the Coryndon Memorial Museum, Nairobi, for the loan of a Leopard Tortoise, and to the Directors of the East African Veterinary Research Organization and of the Veterinary Services, Kenya, for permission to publish this note.
Maximum local helminth parasite community richness in British freshwater fish: a test of the colonization time hypothesis
Authors: Guégan J.-F. , Kennedy C. R. 
Published: June 2009

SUMMARYThe investigation of Price & Clancy (1983), which demonstrated a significant positive correlation between total helminth species number per host species and geographical range of freshwater fish host species in Britain, was re-examined using a different measure of parasite species richness. Re-calculation of the correlations between the two parameters after controlling for the effect of the composition of the list of fish by excluding, on biological and distributional grounds, 2 species of agnathans and 7 species of introduced teleosts, and for the effect of sampling effort by using helminth richness in the richest component community of each fish species rather than check-list data, reveals no significant relationship between helminth species richness and host range. Habitat and an omnivorous host diet now appear more significant determinants of helminth richness than the accumulation of parasites by predation. The findings provide little support for the interpretation of the relationship between helminth species richness and host range in terms of island biogeographic theory, but do support an alternative explanation in terms of the colonization time hypothesis, i.e. that helminth species richness is related to the time since the fish host arrived in Britain.
Common and rare trout parasites in a small landscape system
Authors: Hartvigsen R. , Halvorsen O. 
Published: June 2009

SUMMARYBrown trout (Salmo trutta) from four lakes within an area of approximately 40 km2 were found to harbour nine helminth species. Crepidostomum metoecus could be classified as core species, while Crepidostomum farionis had an intermediate position. All the others could be classified as satellite species. Salmon (Salmo salar) fingerlings were grown to smolts in an earthpond over the summer. The fingerlings became infected with Crepidostomum spp. which may indicate a superior colonization ability in the core species. The results support the ‘rescue effect hypothesis’ rather than the ‘carrying capacity hypothesis’.
Detection ofEchinococcus multilocularisDNA in fox faeces using DNA amplification
Authors: Bretagne S. , Guillou J. P. , Morand M. , Houin R. 
Published: June 2009

SUMMARYIn order to identifyEchinococcus multilocularisDNA in fox faeces for epidemiological purposes, we have developed a new method to prepare DNA suitable for PCR amplification. DNA isolation from fox excrement was performed according to a novel procedure involving lysis in KOH, phenol–chloroform extraction and a purification step on a matrix (Prep-A-Gene®). The target sequence for amplification was theE. multilocularisU1 snRNA gene. PCR products were indistinguishable for 32 differentE. multilocularisisolates and no signal was observed after ethidium bromide staining with DNAs from other tapeworm species, includingE. granulosus.The sensitivity of amplification was monitored by the addition ofE. multilocularisDNA or eggs to faeces free ofE. multilocularisand was estimated to be 1 egg per 4 g of faeces. PCR products were blotted onto nylon membranes and hybridized with an internal oligonucleotide probe in order to confirm the results. Twenty nine faecal samples from foxes shot in Franche-Comté (East France) were tested. Out of 10 samples from foxes in which noE. multilocularisadult worms could be observed after necropsy, 7 were PCR positive, showing that the PCR test is more sensitive than microscopical examination. Out of 19 samples from foxes harbouringE. multilocularisadult worms, 18 were PCR positive. The remaining PCR-negative sample could be due either to the misidentification of the species of adult worm (E. granulosusandE. multilocularis), or to DNA variation between different isolates ofE. multilocularis. Further work in the field should be initiated in order to confirm these results.