bluuebunny/crossref_metadata_2025_split huggingface dataset:
The distribution of a primary infestation of Nippostrongylus brasiliensis in the small intestine of laboratory rats
Authors: Brambell M. R. 
Published: June 2009

The small intestine of rats was divided into twenty sections in a reproducible manner in order to study the distribution of Nippostrongylus brasiliensis by stretching it under a tension of 5g in adrenaline saline.A small but significant difference between the distribution of parasites in male and female rats was observed.As larvae had virtually ceased to reach the intestine by the fifth day all changes in distribution after that day were due to movements of the established adult population.Up to the twelfth day of a primary infestation the majority of the worms were found between the third and tenth sections, the population mode being in the fifth or sixth section. After the thirteenth day the number of worms in this region fell sharply.The female worms had not ceased from egg-laying by the time most of the worms were being rejected.The posterior half of the small intestine, i.e. the eleventh to twentieth sections, was not heavily parasitized, many of the worms seen being in passage to the anus.The first section was not parasitized until the seventh day, but thereafter remained parasitized until long after worms had disappeared from the more posterior sections.The relative number of male worms present increased as the infestation aged.Throughout the experiment the relative number of male worms present at the anterior end of the smaller intestine was higher than that at the posterior.Fourth-stage larvae were found chiefly in the sections that were later most heavily parasitized by adult worms.
The adhesive mechanism of the monogenean parasite Tetraonchus monenteron from the gills of the pike (Esox lucius)
Authors: Kearn G. C. 
Published: June 2009

The monogenean parasite Tetraonchus monenteron attaches itself to the gills of the pike (Esoz lucius) by means of two pairs of large hooks (= hamuli). One pair of hooks is directed ventrally and the outer (flanking) pair is directed dorsally so that the hooks impale two adjacent secondary gill lamellage. Each lateral pair of hooks (one ventral and one dorsal hook) is operated by a single extrinsic muscle, the tendinous region of which is threaded through two fibrous loops (= Pulleys), one attached to each hook. Each tendon on entering the haptor also passes beneath transverse fibres joining the anterior ends of the two ventral hooks and these fibres probably act as a third pulley. This complex pulley system has a high mechanical advantage so that the energy used by the parasite to hold its hooks in position against the strong gill ventilating current of the host is minimal.The mechanics of the adheasive apparatus of T. monenteron are compared with those of the monogenean gill parasite Amphibdelloides maccallumi, in, which the pulley system is less complex.I would like to express my thanks to Mr G. W. Vane who kindly caught some pike for me, and to Dr P. C. Croghan and Mr S. A. Hodson for helpful discussion on the mechanical aspects of the adhesive apparatus.
Light and electron microscope studies of the redia ofParorchis acanthusNicoll
Authors: Rees Gwendolen 
Published: June 2009

Young and old rediae ofParorchis acanthusNicoll, from the digestive gland and gonad ofNucella lapillus(L.) have been described. The young redia has an anterior collar-like fold and mid-ventral birth papilla the movements of which are controlled by a special arrangement of muscles. The birth papilla is ‘solid’ but in older rediae is replaced by a pore. The pharynx is of fairly uniform size irrespective of the size of the redia and the intestine, in the young redia, is relatively muchlarger than in the older redia which facts suggest that relatively more food may be absorbed by the mouth in the young stage. The redia cavity develops as a slit in the central cell mass. As it enlarges the intestine remains close to the dorsal wall and developing embryos are carried, among the cells, towards the surface dropping into the cavity, later, to complete their development. Up to fifty-five cercariae may be present in a redia. Simple nervous and excretory systems are present.The tegument consists of one layer; the surface bears numerous unusual branched microvilli. The syncytial protoplasm contains numerous electron dense mitochondria, vacuoles and granules. Half-desmosomes, not recorded for any other parasitic platyhelminth, occur fairly regularly on the lower limiting layer. Below the uninterrupted basement membrane are circular and longitudinal muscles and, lining the cavity, two or three layers of flattened cells containing numerous mitochondria, agranular and granular endoplasmic reticulum and Golgi complexes. Large lipid globules accumulate in the cells.It is suggested that, in the older redia, active transport of nutrient materials through the tegument may take place.
Taxonomic studies on Archigetes Leuckart, 1878 (Cestoda: Caryophyllaeidae)
Authors: Keneedy C. R. 
Published: June 2009

Recent experimental work has indicated that species of Archigetes are capable of infecting and maturing in fishes in addition to tubificids.The genus Archigetes is re-defined on the basis of morphological and biological characters, with particular emphasis on recent life history studies. All species capable of neotenic development have been re-united in a single genus.A description of all species of Archigetes together with a key for their identification are included. New synonomies are discussed.The relationship of Archigetes to other genera of the family is briefly considered, and it is concluded that it forms the terminal stage in a series showing the attainment of neotenic development.I wish to thank Professor R. J. Pumphrey in whose Department the work was carried out, and Dr J. C. Chubb for advice and help in the preparation of this manuscript. I am also grateful to Professor K. Berg and Dr R. L. Calentine for the loan of specimens. The work was carried out during the tenure of a Nature Conservancy Research Studentship.
Structure and function in the nematode pharynx
Authors: Mapes C. J. 
Published: June 2009

Pumping of the pharynx of Panagrellus has been shown to be a complex process involving three stages: the uptake of a number of globules by the corpus, the passage of the aggregate globule through the isthmus, and expulsion of the globule into the intestine by a number of pumps of the posterior bulb. It is suggested that Aplectana pumps in a similar manner to Panagrellus but at a faster rate. The pharynx of Rhabditis operated in two stages, involving the uptake of food first by the anterior half of the organ, and the subsequent passage of the ingested material through the isthmus and posterior bulb.The pumping action of the posterior bulb suggests that the corrugated valves have a primarily valvular function. Regurgitation of intestinal contents through the pharynx is prevented by the internal pressure of the animals tending to force the walls of the organ together, and by the action of series of valves found throughout the lengths of the pharynges.I should like to thank Professor J. E. Harris and Dr H. D. Crofton for their help during the course of this work, which was carried out during the tenure of a Postgraduate Studentship awarded by the Agricultural Research Council.
Observations on the early migration of the larvae ofAscaris suumGoeze, 1782 in white mice
Authors: Jenkins D. Conwil 
Published: June 2009

The early (0–18 h) migration of the larva ofAscaris suumin the white mouse was studied.The eggs hatched in all gut regions posterior to the stomach, the time of maximal release being between 4 and 8 h after infection. The caecum was the site of maximum larval penetration.Penetrating second-stage larvae produced demonstrable spreading factor reaction with Evan's Blue in the mucosa of the gut. Larvae were located in the venules and lymphatics of the caecum wall as well as in the ileo-colic and hepatic portal veins. Larvae were found in the liver after 9 h and in the lungs 12 h after infection. Larvae were not seen in the muscula externa of the gut and eggs were not found in any region of the body other than the gut lumen.A similar pattern of larval distribution was seen in the gut wall of the rat and the guinea-pig.I am greatly indebted to Dr D. A. Erasmus for his encouragement, advice and supervision during this investigation, and also for carrying out the experimental infections. I also wish to thank Professor J. Brough for the provision of excellent laboratory facilities. Many thanks are due to Mr J. H. M. Hughes (Veterinary Officer) and the meat inspectors at Roath Abattoir who provided me with infected material. I wish to acknowledge the financial support of the Pig Industry Development Authority and the Agricultural Research Council.
A larvicidal evaluation programme using Ascaris suum in mice
Authors: Boisvenue R. J. , Hendrix J. C. , Scholz N. E. 
Published: June 2009

An evaluation programme is presented for determining activity of unknown compounds on Ascaris suum larvae migrating into pulmonary tissues of animals. Data on gross lung lesions due to migrating ascarid larvae were obtained in a series of 44 screening tests consisting of 223 group observations from 1115 mice orally infected with A. suum. Lesion scores were graded in ascending order from 0 to 5 depending upon number and extent of pulmonary haemorrhages. In general, there was no significant difference in lesion scores between untreated mice and mice treated with unknown compounds in their ration. The programme is based on an initial 95% rejection of compounds with a 5% ability to retest compounds in groups of mice.The grand mean score for 44 tests was 2·88. Ninety per cent confidence limits for means among tests established scores at 2·21 and 3·55, and among groups of mice at 1·76 and 4·00, When the test mean was less than 2·2, the ascarid ova used for infection were considered non-virulent. Compounds selected as active were in groups of mice having a mean lesion score of 1·76 or less. Banminth, Styquin and Tetramisole showed larvicidal activity. A reasonable compromise exists in this system wherein false leads are tolerated to avoid screening out effective materials. The host-parasite relationship is proposed as a valuable tool for anthelmintic evaluation.The authors wish to thank Mr W. Henry and Mr M. Jackley of this laboratory.
The larval development of Merizocotyle sp., a monocotylid monogenean from the nasal fossae of Raia undulata
Authors: Kearn G. C. 
Published: June 2009

The oncomiracidium of Merizocotyle sp., a monocotylid monogenean from the nasal fossae of Raia undulata, has 14 marginal hooklets. It seems probable that these larvae swim directly into the nasal fossae or are carried through the nostrils by the olfactory water current without first attaching themselves to the body skin. The marginal hooklets are then supplemented by a pair of hamuli and by 23 suckers, arranged in two concentric rings. The suckers arise as pockets in the ventral surface of the haptor and develop successively in a postero-anterior direction, the inner ring reaching completion before the outer ring.I would like to express my thanks to the Director, Professor R. Weill, and to the Staff of the Station Biologique at Arcachon in France. I am grateful to the Royal Society for a Pergamon Travel Award, which enabled me to visit Arcachon.I would also like to thank Mrs Mary Hutchinson for assistance with histological work.
Changes in adult Nippostrongylus brasiliensis during the development of immunity to this nematode in rats
Authors: Lee D. L. 
Published: June 2009

Ultrastructural studies on adult Nippostrongylus brasiliensis removed at varying stages after infection from rats given a single dose of 2000 infective larvae have shown that changes in their cytology occur and that these can be correlated with the onset and development of immunity to this nematode in the host. The most noticeable changes are resorption of spermatozoa by the male reproductive tract, a drop in egg production, changes in the cytology of the intestinal cells, and the appearance of many large droplets, which look like droplets of lipid, in the cytoplasm of the hypodermis, muscles, excretory glands, reproductive system and the intestine. There are no obvious changes in the structure of the cuticle of the nematode during the course of infection. Possible reasons for the onset of these changes in the nematode are discussed.Much of this work was carried out during the tenure of grants from the U.S. Public Health Service (grant number AI 04275) and from the Agricultural Research Council while I was working at the Molteno Institute in Cambridge. I wish to thank the late Professor J. D. Boyd and Dr C. C. D. Shute of the Department of Anatomy, Cambridge, for permission to use the electron microscopes, Mrs B. Fisher for technical assistance and Mr Paul Rogers for assistance with the photography.
A new haemosporidian of lizards, Saurocytozoon tupinambi gen.nov., sp.nov., in Tupinambus nigropunctatus (Teiidae)
Authors: Lainson R. , Shaw J. J. 
Published: June 2009

Saurocytozoon tupinambi gen.nov., sp.nov. (Haemosporidiidea, Leucocytozoidae) is described in the teiid lizard, Tupinambus nigropunctatus, from Pará State, Brazil. This would appear to be the first record of a member of this family in a reptile; the existing genera Leucocytozoon and Akiba are known only in birds.The gametocytes of S. tupinambi develop within lymphocytes and immature erythrocytes. Only developing and mature gametocytes are found in the peripheral blood: morphologically they are very similar to the gametocytes of Leucocytozoon and Akiba. No mega-schizonts or other tissue stages have yet been detected.Aedes spp., have been trapped while feeding on Tupinambus in areas where infected lizards have been caught, and may possibly be the vectors.We are indebted to Professor P. C. C. Garnham, the London School of Hygiene and Tropical Medicine, London, who has examined our material and offered his invaluable opinions.The cost of the colour plate was defrayed by the Wellcome Parasitology Unit, Instituto Evandro Chagas, Fundaçao Serviço Especial de Saúde Pública, Belem, Pará, Brazil.
Acquired immunity to Babesia microti and Babesia rodhaini in mice
Authors: Cox F. E. G. , Young A. S. 
Published: June 2009

Mice infected with Babesia rodhaini can be cured with a single injection of Diampron and are immune to challenge with the same species. Mice infected with B. microti recover naturally from their infections and are also immune to challenge. The immunity extends to the heterologous species in both infections. In some cases parasites persist at a low level after recovery but in others the immunity is of a true sterile type. Immunity once established is unaffected by splenectomy in mice which have recovered from B. rodhaini and challenged with either B. rodhaini or B. microti.We wish to express our thanks to May and Baker Ltd. who kindly provided us with the Diampron used in these experiments.
Demodex auratisp.nov. andD. criceti, ectoparasites of the Golden Hamster (Mesocricetus auratus)
Authors: Nutting Wm. B. 
Published: June 2009

A new species,Demodex aurati, is described from the Golden Hamster,Mesocricetus auratus. It differs in both morphological detail and ecological niche fromD. cricetipresent on the same host.When pieces of heavily parasitized skin were ‘subplanted’ for 100 days no change in morphological features of eitherD. auratiorD. cricetioccurred.D. auratiis a low grade pathogen, apparently only harvesting the cells of the follicular epithelium.The life cycle ofD. auratiis described.The presence on one host species of two different species of this genus, which has affinities with demodicids of evolutionally remotely related hosts, poses an interesting problem in species specificity and ectoparasite evolution.I wish to thank Dr Miriam Shaw, Miss Shirley DiBenedetto and Miss Helen Krause for their excellent technical help, and Dr Lawrence Bartlett and Dr Harold Rauch for perusal of the manuscript and suggestions on project procedure.This investigation was supported by a research grant E-562 from the Institute of Allergy and Infectious Disease, of the National Institutes of Health, Public Health Service.
The structure and function of the adhesive organ in strigeid trematodes
Authors: Öhman Christina 
Published: June 2009

The biology and life cycle of Apatemon gracilis minor is briefly described.The morphology of the cup–shaped forebody with the small lappets, the pear-shaped subcuticular cells and the very flexible finger–like adhesive organ lobes is considered in some detail.An extensive description of the body musculature is given and the mode of attachment of the parasite to the host mucosa is studied.The main results of the histochemical tests are: (a) a relative absence of enzymes in the adhesive organ and a greater activity in the lappets; (b) the presence of two types of esterase, a non-specific esterase of B-type in the caecal cells and a non-specific esterase of resistant type, possibly a non-specific cholinesterase, in the rest of the reacting sites in the parasite; (c) a relatively small activity for leucine aminopeptidase; (d) the presence of RNA at all sites of enzyme formation; and finally, (e), the presence of enzymes and carbohydrates in the cuticle.The activities of the parasite result in a local disruption of the host intestinal mucosa at the site of attachment. It is suggested that this is a result of the activities of the enzymes secreted by the parasite.The absorption of nutrients and the circulatory function of the excretory system are discussed.I should like to express my sincere thanks to Dr D. A. Erasmus for helpful discussions and advice during the progress of the work and to Professor J. Brough for giving me the opportunity to work in his department. The study was conducted during the tenure of a grant from Svenska Vetenskapliga Centralrådet i Finland.
Immunity to Trichinella spiralis
Authors: Denham D. A. 
Published: June 2009

Single infections of Trichinella spiralis of 48 h duration did not produce a significant degree of immunity in mice.Single or triple light infections of 7 h duration which, it is suggested, were composed entirely of fourth-stage larvae, did not produce significant immunity.Single infections of 3 or 4 days duration did produce immunity. It is suggested that the fourth-stage intestinal larvae and the fourth moult are not the most important sources of immunizing antigen in a T. spiralis infection.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 being conducted. I would also like to thank Professor W. I. B. Beveridge, within whose department this work was conducted, for the facilities provided. The helpful advice of my colleagues R. M. Connan and R. S. Phillips was of great value during the time that this manuscript was being prepared for publication.
Rhipicephalus carnivoralissp.nov. (Ixodoidea, Ixodidae) A new species of tick from East Africa
Authors: Walker Jane B. 
Published: June 2009

A description is given of the male, female, nymph and larva ofRhipicephalus carnivoralissp.nov., a parasite of carnivores in East Africa, and its affinities within the genus are discussed.Its developmental periods under laboratory conditions are given and its hosts and distribution in the field are recorded.The author wishes to thank the Director of the East African Veterinary Research Organization for permission to publish this paper. She is also most grateful to all who made field collections of this species for her; to the British Museum (Natural History), London, for the loan of specimens from their collection; to J. P. J. Ross for the loan of specimens from his collection and to D. W. Brocklesby and K. P. Bailey, who carried out the experiments on the transmission of East Coast fever. Dr G. Theiler, Mr G. H. Yeoman, Mr G. M. Kohls, Dr C. M. Clifford and Dr H. Hoogstraal kindly checked the manuscript before publication and made helpful suggestions. Finally, she would like to thank Professor P. C. C. Garnham and Dr Charles Wilcocks for their advice on the name of this tick.
The development of resistance to glycarbylamide and 2-chloro-4-nitrobenzamide in Eimeria tenella in chicks
Authors: Ball S. J. 
Published: June 2009

A twofold increase in resistance to glycarbylamide was induced in a strain of Eimeria tenella in chicks. This strain remained susceptible to amprolium, nicarbazin, nitrofurazone, zoalene, 3,5-dinitrobenzamide, 2-chloro-4-nitrobenzamide (M & B 5921) and spiramycin.At least an eightfold resistance to 2-chloro-4-nitrobenzamide (M & B 5921) was developed in another strain of E. tenella. This strain was also resistant to nitrofurazone, zoalene and 3,5-dinitrobenzamide, but not to glycarbylamide, amprolium, nicarbazin and spiramycin.A single test showed no transfer of drug-resistance when the two resistant strains were given simultaneously to the same birds.When a small number of parasites of a glycarbylamide-resistant strain of E. tenella was introduced into a larger inoculum of the normal parent strain, the resistant individuals appeared to diminish in number during passages through untreated chicks.I wish to thank Mrs B. M. Mitchell, Miss C. A. Hitchcock and Miss J. Watkins for technical assistance at various stages of the work.
The structure and development of the macrogamete and oocyst of Eimeria acervulina
Authors: Lee D. L. , Millard B. J. 
Published: June 2009

The fine structure of the macrogametocyte, macrogamete and the early stages in the formation of the oocyst wall of Eimeria acervulina have been described and compared with other species of Eimeria. It has been shown that type II wall-forming bodies are formed in cisternae of the granular endoplasmic reticulum in association with Golgi complexes. The developing oocyst has been shown to be enclosed by three membranes: the outermost is the original membrane of the merozoite and macrogametocyte; the second membrane appears when the wall-forming bodies are appearing in the cytoplasm of the macrogametocyte and the innermost membrane appears after fertilization. The wall-forming bodies discharge their contents between the innermost membrane and the middle membrane.We wish to thank Mr P. L. Long for much valuable discussion, Mrs B. Fisher for technical assistance and Mr B. Carter for assistance with the photography.
The locomotion of the acanthor ofMoniliformis dubius(Archiacanthocephala)
Authors: Whitfield P. J. 
Published: June 2009

The mature egg and the acanthor ofMoniliformis dubiushave been redescribed with special emphasis on the features relevant to the locomotion of this larval acanthocephalan. The movements of acanthors have been analysed by the use of frame by frame study of filmed records of motile acanthors. Acanthors appear to use the same mode of locomotion for hatching, locomotion within the gut of the intermediate host and penetration of the host's gut wall. Movement is produced by a set of spiralled, longitudinal muscles in the body wall of the hind body and two rostellar retractor muscles. This musculature acts both directly on the body wall and indirectly by hydraulic effects via the hydrostatic skeleton of pseudocoelomic fluid. The spiny evertable rostellum and the backward facing spines of the hind body are the means whereby shape changes of the acanthor interact with the immediate environment to produce effective progression.I should like to thank Professor D. Arthur for the provision of laboratory facilities, Dr D. W. T. Crompton for the initial gift of eggs ofM. dubiusand Mr R. D. Reed for invaluable assistance with microcinematographic technique. The work was carried out during the tenure of a Nuffield Foundation Research Fellowship.