bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental evidence of genetic determinism in high susceptibility to intestinal pinworm infection in mice: a hybrid zone model
Authors: Moulia C. , Brun N. Le , Dallas J. , Orth A. , Renaud F. 
Published: June 2009

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

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

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

The tetrad and companion cells, in association with the oesophagus and dorsal tract of tissue, of Tetradonema plicans, have been investigated in the host Bradysia paupera. The companion cells contain glycogen and mucopolysaccharide. The tetrad cells are rich in RNA and probably synthesize protein and secrete some as enzymes. The gut is functional and the oesophagus is in connexion with the tetrad. The dorsal tract is not connected with the oesophagus or tetrad and contains lipid with characteristics similar to that found in the eggs.It is suggested that the tetrad and companion cells are homologous with the stichocytes present in the Trichuroidea and some members of the Mermithoidea.I am grateful to Professor T. R. E. Southwood in whose department this work was carried out. I should like to thank Dr N. A. Croll for supervising and encouraging this work and Dr T. Jenkins for his helpful criticism and advice. The work was supported by the Agricultural Research Council.
The stability of resistance to diminazene aceturate and quinapyramine sulphate in a strain ofTrypanosoma vivaxduring cyclical transmission through antelope
Authors: Gray A. R. , Roberts C. J. 
Published: June 2009

A drug-resistant strain ofT. vivaxwas transmitted through a series of four duikers (S. grimmia) and a gazelle (G. rufifrons) byG. palpalisandG. tachinoides. The cyclical transmission of the strain in cattle, started in earlier work, was continued for control purposes. Infections with the drug-resistant strain in the antelope were of the same type as those produced by field strains ofT. vivaxin the same host species, and infection rates in tsetse flies fed at early stages of infection on the antelope were similar to those found in flies fed on cattle infected with the drug-resistant strain. The strain retained resistance to diminazene aceturate at a dose rate of 7-0 mg/kg and quinapyramine sulphate at 5'0 mg/kg in the absence of the drugs for 7 months in tsetse flies and antelope, and for a total period of 29 months in tsetse flies and cattle.We wish to thank Dr A. A. Amodu, Director of the Nigerian Institute for Trypanosomiasis Research, for permission to publish this paper.
Polymerase chain reaction—identification of Dirofilaria repens and Dirofilaria immitis
Authors: Favia G. , Lanfrancotti A. , Torre A. Della , Cancrini G. , Coluzzi M. 
Published: June 2009

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

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

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

A standard culture technique is described for obtaining the various developmental stages of Trichostrongylus colubriformis, and a suitable technique for assessing the effect of methyl bromide fumigations is outlined.Doses of 10, 25 and 150 mg. hr./l. were required to give an LD50 for eggs, pre-infective and infective larvae respectively. The age of infective larvae, the relative humidity and the temperature all influenced the toxicity of the fumigant. Soil, and more especially faeces, sorb the fumigant and probably protect larvae from its full effect. Infective larvae of T. axei, T. retortaeformis and H. contortus were also found to be susceptible to methyl bromide.The activity of larvae surviving fumigation was considerably reduced, but these larvae were still capable of infecting guinea pigs.Methyl bromide killed common pasture grasses at doses of 150–250 or more mg. hr./l., depending on the temperature. Chloropicrin was found to be highly toxic to grass and unsuitable where the pasture is required undamaged.The results are discussed in the light of current theories of the mode of action of methyl bromide on insects and what is known at present of the physiology of nematodes.It is concluded that under certain conditions, methyl bromide might be used to eliminate infestations of trichostrongyle larvae on pasture, without killing the pasture.I am indebted to Professor B. G. Peters and other members of the staff of the Imperial College Field Station and Dr C. W. R. Spedding of the Grassland Research Institute, Hurley, for their help in this work and their advice and criticism.
Structure and function in the nematode pharynx
Authors: Mapes C. J. 
Published: June 2009

The simple cylindroid pharynx ofAscaris lumbricoideshas been shown to be characterized by a pharyngo-intestinal valve which is composed of two sets of valves. This is the only valve structure in the pharynx of this nematode. The pharynges ofOxyuris equi, Aplectana brevicaudataandPanagrellus silusiaehave a series of valve structures along the lengths of the organs. All these types have a valve at the anterior end of the corpus, corrugated ‘valves’ in the posterior bulb, and pharyngo-intestinal valves. A valve between the corpus and the isthmus has been shown inOxyuris.In all the nematodes studied the pharyngo-intestinal valve is characterized by an overlapping of the muscle fibres associated with the valve and the main musculature of the pharynx that immediately precedes them. It has been suggested that the pharyngo-intestinal valves of the types studied may have evolved from the type of valve found in the Enoplina.The marginal tissues of the pharynx ofAscaris lumbricoideshave been shown to be composed of three types of tissues. It has been suggested that the marginal tissues have a suspensory and skeletal function. The suspensory strands subserve the first function, while the investing strands and the associated fibrous layer provide a longitudinal skeletal structure in the pharynx. InOxyurisno fibrous layer is associated with the marginal tissues.I would like to thank Professor J. E. Harris and Dr H. D. Crofton for their help and criticism during the course of this work, which was carried out during the tenure of a Postgraduate Studentship awarded by the Agricultural Research Council.
The physiology of excystment of the metacercaria ofFasciola hepaticaL.
Authors: Dixon K. E. 
Published: June 2009

Excystment of the metacercaria ofFasciola hepaticais an active process and occurs in two stages—activation and emergence. Activation is initiated by high concentrations of carbon dioxide, reducing conditions and a temperature about 39 °C. The reducing conditions increase the rate of action of the other two stimuli. The carbon dioxide stimulus need only be applied for 5 min, but the exposure time to the reducing conditions has to be of the order of 30 min. Changes in the order of application of the stimuli carbon dioxide and redox potential have no effect.The second phase, emergence, is triggered by bile. Metacercariae were held in an activated condition for 24 h, and when bile was added emergence took place normally.During excystment the metacercariae exhibit a complex behaviour pattern. After activation there is an initial period of rotatory activity, but after about 20 min a quiescent phase ensues when the metacercariae contract away from the cyst wall at an imperceptible rate. This behaviour occurs in response to stimulus from a high concentration of carbon dioxide and a temperature about 39 °C. When the metacercariae are exposed to bile the second phase of activity is initiated, consisting of antero-posterior thrusting movements directed against the ventral side of the cyst wall. Within about 15 min the juvenile flukes escape through a small circular hole in the ventral surface of the cyst wall which corresponds to the ventral plug region.
The fate of the sporozoites of Eimeria acervulina, Eimeria maxima and Eimeria mivati in the caeca of the fowl
Authors: Horton-Smith C. , Long P. L. 
Published: June 2009

The sporozoites of Eimeria acervulina and E. maxima when injected into the caeca of chickens fail to produce infections. Sporozoites of E. mivati injected into the caeca invade the walls and the life-cycle is completed. These observations are discussed in their relation to the fate of sporozoites injected into the allantois of chick embryos. The possible use of these techniques in confirming the identity of a species is discussed.We wish to thank Mr B. J. Millard for technical assistance with the preparation of the sporozoites.
Small spines on the egg shells of Schistosoma
Authors: Hockley David J. 
Published: June 2009

Small spines of maximum size 0.28 μm × 0.5 μm have been found all over the shells of the eggs of Schistosoma mansoni and S. haematobium. The small spines on S. haematobium eggs are less pointed than those on S. mansoni eggs. They consist of inner and outer parts made up of subunits, and they are continuous with the main part of the shell underneath. S. mansoni eggs still within the blood vessels of the gut have extracellular material between the spines and there is cell debris over them. The scanning electron microscope shows the increased surface area of the egg shell due to the small spines.I wish to thank many people for their help with this work and in particular Dr F. Hawking, Dr S. R. Smithers and Mrs. L. Ebden.
Nematode parasites of Oceanica. IV. Oxyurids of mammals of Palawan, P.I., with descriptions of four new species of Syphacia
Authors: Schmidt Gerald D. , Kuntz Robert E. 
Published: June 2009

Syphacia (Syphatineria) oceanica sp.nov. is described from the squirrel Sundasciurus steerii juvencus. It is closest to S. transafricana Chabaud & Biocca, 1955, differing from it in having a cephalic vesicle, an isthmus between oesophagus and bulb, and in characteristics of the gubernaculum. Syphacia (Syphacia) critesi sp.nov. is described from S. steerii juvencus and the flying squirrel Hylopetes nigripes. It is closest to S. thompsoni Price, 1928, differing from it in lacking cephalic vesicle, alae, and cervical papillae; in having a long oesophagus and shorter gubernaculum Syphacia (Syphacia) magnispicula sp.nov. is described from H. nigripes and S. steerii juvencus. It is characterized by having a spicule 312–338 μm long, much longer than any species yet reported. Syphacia (Syphacia) coli sp.nov. is described from H. nigripes and the rat Rattus exulans luteiventris. It is closest to S. critesi sp.nov., differing from it in sizes and shapes of oesophagus and gubernaculum, in having lateral alae, and in egg size. Syphacia sp. is reported from Rattus exulans luteiventris; Blattophila sp. is reported from the skunk Mydaus marchei; and Allodapa sp. is reported from Sundasciurus steerii juvencus.The authors wish to express their appreciation to Dr D. S. Rabor, Silliman University, Dumageute, Negros Oriental, Republic of Philippines, for general support in field activities and for tentative host identifications; Mr Max Thompson, Bishop Museum, Honolulu, for assistance in collection of hosts and Dr David H. Johnson, Research Curator, Division of Mammals, U.S. National Museum Washington, D.C., for final host identifications. Thanks are extended to Dr W. G. Dyer and Dr P. D. Leiby, Minot State College, for technical assistance during the course of this work, and to Dr W. W. Becklund, Beltsville Parasitological Laboratory, for the loan of specimens for comparative purposes. Special thanks are due to Mrs MayBelle Chitwood, whose efforts greatly improved the quality of this work.
Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from Raja naevus with a comment on its habitat and mode of attachment
Authors: Williams H. Harford 
Published: June 2009

Phyllobothrium piriei sp.nov. (Cestoda: Tetraphyllidea) from the intestine of Raja naevus in the North Sea resembles P. dagnallium, P. radioductum and P. britannicum more closely than any other known species of the genus but differs from these mainly in its host, in having distinctly bifid bothridia with faint marginal loculi and about 150 testes in each proglottid. Brief comments are made on the preference shown by the adult for the posterior region of the intestine and on a modification of its bothridium for attachment to up to 12 villi.This work was supported by generous financial aid from the Natural Environment Research Council. I wish also to record my gratitude to Professor V. C. Wynne-Edwards and Dr P. A. Orkin for reading and suggesting improvements to the manuscript and to the Director and staff Marine Laboratory, Aberdeen, in particular Dr B. B. Rae and Mr Stuart Pirie, after whom this species has been named, for providing live rays. Alasdair McVivar of this department, who has now begun an independent study of the intestine of Raja naevus as a habitat for helminth parasites, kindly provided information for Fig. 9.
Passive protection with cells or antiserum against Nippostrongylus brasiliensis in the rat
Authors: Ogilvie Bridget M. , Jones Valerie E. 
Published: June 2009

Rats can be passively protected against N. brasiliensis either with antiserum or with cells. Only some pools of antiserum (15 of 48 pools) and a few batches of cells (three of 11 batches) were protective.Protective activity was found in serum taken after one infection as frequently as after several infections and gave the same degree of protection. This suggests that second and subsequent infections do not stimulate an anamnestic increase in protective antibodies in the circulation.Serum and cells taken from the same rats were unrelated in their protective capacity; sometimes serum protected when the cells were ineffective and the reverse also occurred.Cells transferred from the spleen, peritoneal cavity or mesenteric lymph nodes were capable of initiating reagin formation, irrespective of their ability to protect against N. brasiliensis.When protection was achieved with transferred cells, the parasite life-cycle was shortened by only 1–2 days.We have found no evidence that a delayed mechanism of the homograft type is concerned in immunity to N. brasiliensis in the rat.We thank Miss W. D. Griffiths and Mr A. J. Edwards for their willing assistance. The statistical analysis was kindly done for us by Miss M. V. Mussett of the Statistics Department at our Institute.
Parasites as biological models
Authors: Smyth J. D. 
Published: June 2009

The value of metazoan parasites as models for the investigation of fundamental biological phenomena is discussed. The fields in which they are of particular value include: immunology, neuromuscular physiology, nucleo-cytoplasmic relationships, genetics, cyto-differentiation, comparative biochemistry.After reviewing some examples of experimental organisms in trematodes and nematodes, the cestode,Echinococcus granulosus, in particular, is examined as a model.Problems of particular interest in this organism are: the function of the rostellar gland, whose cells release a secretion which has its origin in the nuclei of these cells; the mode of action of the suckers, whichin vivoare thought to remain in a state of sustained contraction; the mode of digestion at the host–parasite interface—membrane digestion appears to be involved; the various modes of membrane transport through the tegument; factors controlling cystic or strobilar differentiation, a problem viewed in the light of the Jacob–Monad model of gene action.A hypothetical control circuit for differentiation of the stages in parasite life-cycles in general is also put forward.Some preliminary experiments on thein vitroculture ofTaenia serialis, are described. The factors controlling differentiation into cystic or strobilar directions appear to be generally similar to those which operate forEchinococcus granulosus.It was stressed that many other species of parasites could also serve as models for investigating similar or related problems.Some of the studies described here were supported by grants from the Australian Wool Board, the U.S. Public Health Service (Grant no. A 107452–02) and the Rural Credits Development Fund.I am grateful to Mr D. Heath for the provision of the micrographs ofTaenia pisiformisandT. serialisin P1. 2, figs. 2, 3.