bluuebunny/crossref_metadata_2025_split huggingface dataset:
The rapid development of the glucose transport system in the excysted metacestode ofHymenolepis diminuta
Authors: Rosen R. , San M. L. , Denton M. E. , Wolfe J. M. , Uglem G. L. 
Published: June 2009

SUMMARYTemporal changes in glucose transport capacity in excysted scoleces ofHymenolepis diminutawere examined. Assays involved incubation for 1 min in [3H]glucose after pre-incubation for 1 min to 8 h in saline. There were two abrupt increases in uptake velocity, a relatively small one between 15 and 75 min, and a large one between 5 and 6 h, during which theVmaxincreased from 0·36 to 2·49 nmol/25 larvae/h. The second increase was unaffected when the pre-incubation saline contained 5 mM glucose, but it was completely blocked when the excysted larvae were pre-incubated in Ca2+-free saline. Abrupt glucose transport changes did not occur in intact cysticercoids or in scoleces when the substrate was [3H]leucine or [3H]uracil. Arrhenius plots (logVversus 1/temperature, 10–42 °C) were linear for intact cysticercoids, but were biphasic for both scoleces and adults with discontinuities at 20 ± 1 °C. Thus, ‘activation’ of the excysted scolex seemed to involve a specific, Ca2+-dependent increase in number of glucose transporters functioning in the worm surface. The Arrhenius plots indicated that development in the final host does not involve a major change in lipid composition of the parasite's membranes.
Two species of Peritrichous Ciliata epibiotic on parasitic Crustacea from Lake Albert, Uganda
Authors: Green J. 
Published: June 2009

Rhabdostyla elongata sp.nov. is described and figured. This peritrich was found as an epibiont on Lernaea barnimiana, a copepod parasitic on the Nile Perch, Lates niloticus in Lake Albert.Epistylis articulata Fromentel is recorded as an epibiont of Dolops and Argulus, which parasitize a wide range of fish in Lake Albert.My thanks are due to Mr M. J. Holden who identified the fish as they were removed from the nets, and to Dr G. Fryer, who identified Lernaea barnimiana and has helped with the literature. I am also grateful for a grant from the Leverhulme Trust which made possible the collection of this material.
The structure and histochemistry of the cyst wall of the metacercaria ofFasciola hepaticaL.
Authors: Dixon K. E. 
Published: June 2009

The cyst wall which encloses the metacercaria ofFasciola hepaticaconsists of four major layers, one of which is further divisible into three sublayers. These layers are numbered I to IV, the first being the external layer. Layers I and II form the outer cyst which may be separated from the inner cyst formed from layers III and IV.Layer I, the thick incomplete external layer, covers the metacercaria dorsally and laterally. It is composed of tanned protein.Layer II is a thin fibrous layer closely adherent to the inner surface of layer I and is composed of mucoprotein and acid mucopolysaccharide.Layer III is made up of three separate sublayers, the relative widths of which vary in different regions of the cyst. In general IIIaconsists of mucoprotein, IIIbof acid mucopolysaccharide and IIIcof neutral mucopolysaccharide.In the dorsal and lateral regions, layer IV appears to be formed of lamellae held in a protein–lipid matrix. The lamellae are composed of protein stabilized by disulphide linkages.In the ventral region of layer IV there is a thickened mucopolysaccharide area, the ventral plug, through which the metacercaria excysts.The relative importance of these resistant layers in providing protection against desiccation, toxic substances and attack by other organisms is discussed.This work was carried out during the tenure of a Commonwealth Post Graduate Scholarship. The author is grateful to Professor J. D. Smyth and Dr J. A. Clegg for advice and encouragement during the course of this work and in preparation of the manuscript.
The growth of some species of Eimeria in avian embryos
Authors: Long P. L. 
Published: June 2009

Four species of Eimeria from fowls were able to develop in chicken embryos following the inoculation of sporozoites. Three species (E. brunetti, E. mivati and E. tenella) were able to complete the whole of their endogenous cycle in embryos. E. necatrix developed to late schizogony, E. acervulina and E. maxima did not develop.The life-cycles appeared to be delayed, and in the case of E. tenella embryo mortality was associated with heavy parasitism of the chorioallantoic membranes. Oocysts recovered from urate deposits in the allantoic cavity sporulated normally and induced infections in chickens.Attempts to infect turkey and quail embryos with E. tenella or chicken and turkey embryos with E. stiedae were unsuccessful.The implications of the findings are discussed.I wish to thank Dr C. Horton-Smith for his encouragement and guidance with this work; Dr M. E. Rose for help in the preparation of the manuscript and Mr B. J. Millard for careful technical assistance.
The host-parasite interface of Cyathocotyle bushiensis Khan, 1962 (Trematoda: Strigeoidea)
Authors: Erasmus David A. 
Published: June 2009

A combination of histochemical and electron microscope techniques have demonstrated, in Cyathocotyle bushiensis, alkaline phosphatase activity in the matrix of the tegument, in the distal and basal plasma membranes of the tegument, in the wall of the ducts extending from the adhesive organ gland cells and in the wall of the adhesive organ microvilli. Acid phosphatase activity was much stronger and was present in the tegument matrix and in the granular component of the secretion from the adhesive organ gland cells. Strong acid phosphatase activity was also present in the cisternae of the endoplasmic reticulum of the adhesive organ gland cells.I am greatly indebted to Professor Brough for the excellent facilities available within this department. I also wish to thank Professor J. Sinclair (Department of Mining) for electron microscope facilities extended to me in the early stages of this investigation, and to Mr W. Henderson, Mr T. Davies and Miss M. Williams for their invaluable assistance. The purchase of the Huxley ultramicrotome, coating unit and an AEI EM 6 electron microscope was made possible by a grant from the Science Research Council.
Immunity to coccidiosis: protective effect of transferred serum in Eimeria maxima infections
Authors: Rose M. Elaine 
Published: June 2009

Serum taken between 2 and 3 weeks after infection of the donors with E. maxima conferred a considerable degree of protection against infection with the homologous organism when injected daily into young recipients. Different pools of such sera had differing activities, but the majority gave protection of 50% or more whereas a few were inactive.The degree of protection obtained was dose-dependent, varying directly with the volume of serum injected and inversely with the size of the challenge oocyst inoculum.A course of injections started early in the life-cycle had a greater effect than those started in mid- or late cycle even when comparatively large volumes of serum were given.Protection was species specific; serum obtained from birds infected with E. maxima did not protect against E. praecox or E. acervulina.The assistance of Mrs Patricia Hesketh is gratefully acknowledged, as is the help of other members of the staff of the Parasitology Department. Mr P. Townsend, Senior Poultry Attendant, supervised the cleaning and sterilization of cages and the collection of faecal samples.
Studies on gut ultrastructure and digestive physiology in Cyathostoma lari (Nematoda: Strongylida)
Authors: Colam J. Barry 
Published: June 2009

Histological, histochemical and ultrastructural methods have been used to study the gut structure and digestive physiology in the parasitic nematode Cyathostomalari E. Banchard, 1849. The nematode is parasitic in the orbito-nasal sinuses of its host and feeds exclusively upon blood.Three gland cells are present in the oesophagus, one in each sector. The two subventral gland ducts open into the lumen of the oesophagus at the level of the nerve ring, and the dorsal gland duct into the base of the buccal capsule. It is suggested that the latter gland may produce an anticoagulin, histolytic and/or haemolytic secretions, histochemically-inactive in situ. The intestine is syncytial, with no differentiation into secretory components, and its distal surface is provided with a prominent brush border of long microvilli.A non-specific esterase, thought to originate in the oesophageal gland secretions, causes haemolysis of ingested erythrocytes. The major part of haemoglobin digestion is extracellular, partly by a process of contact digestion on the microvilli, initiated by the esterase, and the protein is then further broken down by an exopeptidase of the ‘leucine aminopeptidase’ type, and the products absorbed into the gastrodermis possibly with the aid of an acid phosphatase present on or in the microvilli. An insoluble iron-containing compound, which is not haematin, results from breakdown of the prosthetic group. A smaller proportion of haemoglobin is taken up by the gastrodermis and digested intracellularly by the action of lysosomal hydrolases. An endopeptidase and an acid phosphatase are present in the gastrodermis, possibly in sacs of GER which are suggested to be primary lysosomes and which fuse with the endocytosed heterophagosomes. The insoluble pigment haematin results from digestion within the heterolysosomes, and this gives rise to the iron-containing gastrodermal pigment granules. The products of extracellular digestion are absorbed by the gastrodermis where they are synthetized into lipid by a lipase, which probably resides in whorls of GER.This investigation was supported in part by Research Grant AI 06295 of the United States Public Health Service. The final manuscript was prepared during the tenure of a Postdoctoral Fellowship from the British Egg Marketing Board. I wish to extend my gratitude to Dr J. B. Jennings for advice and encouragement throughout this work.
The dynamics of the host–parasite relationship
Authors: Dineen J. K. , Wagland B. M. 
Published: June 2009

The response of sheep given six sensitizing infections each of 3000 infective larvae of H. contortus at fortnightly intervals to a challenge infection of 3000 infective larvae has been studied. While a large proportion of the challenge infection (ca. 3000 parasites) persisted to termination of the experiment on day 141 in sheep (group 3) in which the challenge was superimposed upon the sensitizing infections, only a mean of 437 worms, including both 4th-stage larvae and adults, was recorded at this time in another group (group 5) in which the sensitizing infections were terminated by anthelmintic treatment on day 90, i.e. 8 days before challenge. The proportion of the total worm burdens of the challenge infections arrested at the 4th larval stage was increased for both groups (25% for group 3 and 18% for group 5) by comparison with unsensitized control groups (4% for group 6 and 2% for group 7).As the effect of immunological control was expressed more vigorously in the group (group 5) in which the sensitizing infections were terminated before challenge it seems likely that recovery of immunological competence occurred in these animals following removal of the sensitizing infections. This conclusion suggests that, owing to the persistence of the sensitizing infections and therefore exposure of the immune mechanism to continuous antigenic insult, the animals which received the superimposed challenge infection had entered a phase of immunological exhaustion during the challenge period.
Population studies on the infective stage of some nematode parasites of sheep I. The frequency distribution of strongyloid infective larvae in random samples of pasture
Authors: Donald A. D. 
Published: June 2009

Observations have been made on the frequency distribution of strongyloid infective larvae in random samples of pasture herbage collected on four occasions from a quarter-acre field grazed by five sheep carrying mixed strongyloid infections. The distribution of numbers of infective larvae of the genera Haemonchus, Trichostrongylus and Cooperia in each of the samples has been examined. The variance of each series was found to be substantially larger than its mean and, hence, the distributions were all highly overdispersed statistically. Of a number of frequency distribution models, the ‘truncated lognormal’ was found to provide the best empirical fit to the sample distributions.The implications of these findings for determining the significance of the difference between two random sample estimates of the abundance of infective larvae in pasture, have been discussed. It has been shown that, because of the limit imposed by technical considerations on the maximum size of herbage samples, and because the distribution of infective larvae in pasture departs markedly from a random one, only quite large differences between the means of two random sample estimates are likely to be significant. However, because the numbers of infective larvae of the different strongyloid genera are highly correlated within sample units, considerably smaller differences between the means for different genera, within the same sample, can be detected as significant.From a consideration of the complexity of the biological components generating populations of infective larvae on pasture, it has been concluded that simple frequency distribution models can contribute little towards an improved understanding of the population dynamics of strongyloid infective larvae in pastures grazed by sheep.
Reaginic antibodies and immunity toNippostrongylus brasiliensisin the rat
Authors: Ogilvie Bridget M. , Jones Valerie E. 
Published: June 2009

Rats thymectomized at birth were infected withNippostrongylus brasiliensisat 6 weeks of age. In some, but not all, rats egg production was greatly prolonged after the primary infection. Thymectomized rats were less resistant than controls to second infections.In rats infected at birth the development of resistance was significantly delayed. Neonatally infected rats, when they were 6 weeks old, were less resistant to reinfection than adult controls. Rats infected three times in the neonatal period were more resistant to challenge at 6 weeks of age than rats infected once at birth, but less resistant than adult controls. The degree of immunity induced by a single neonatal infection was variable; some rats showed little or no resistance to reinfection 6 weeks later.Antibody formation, measured by the occurrence of reagins, was altered in the same way by both neonatal thymectomy and neonatal infection. In the thymectomized (immunologically deficient) and newborn (immunologically immature) rats, reagin formation following initial infection was delayed; there was a reduced anamnestic response after challenge; mean titres were lower and more variable than in control animals; and in some rats circulating reagins were never detected.In thymectomized rats the capacity to demonstrate anaphylaxis was as variable as in control rats, but in the few thymectomized rats in which egg production was prolonged, anaphylaxis was slight at a time when most intact rats had developed the capacity to show anaphylaxis. Rats infected at birth and adult rats infected at the same time were equally susceptible to systemic anaphylaxis 6 weeks later, although by this time there was a marked difference in the degree of resistance to the parasite developed by the two groups.In adult rats splenectomy before, during or after initial infection had no effect either on the rate of development, or the degree of immunity induced by primary or secondary infections, or on antibody formation.We would like to thank Miss W. Griffiths and A. J. Edwards for their willing technical assistance. This work was done whilst one of us (B.M.O.) was the holder of a Wellcome Fellowship of the Animal Health Trust.
The structure and possible function of the signum ofGlossina tabaniformisWestwood
Authors: Jordan A. M. 
Published: June 2009

1. In all species of thefuscagroup of tsetse flies (Glossina), exceptG. brevipalpisNewstead, a gelatinous structure, the genital fossa, is present at the anterior end of the uterus. On the surface of the genital fossa is a toughened structure known as the signum.2. Probably chitin and certainly calcium are present in the substance of the signum ofG. tabaniformisWestwood. An opaque concretion develops on the signum after the female has been fertilized. The concretions may be caused by a reaction between sperms or secretions from the male accessory glands and materials in the substance of the genital fossa; the possibility that the concretions are ‘mating scars’ produced by pressure of the harpes of the male on the signum is considered unlikely. Concretions are not present on the signa of all species.3. A possible mechanism of fertilization inG. tabaniformisis discussed, and it is suggested that the signum may act as a protective shield for the anterior part of the uterus and common oviduct of the female from the harpes of the male which are inserted into the uterus during coitus. The views of Machado (1959) are discussed and it is agreed that the signum probably acts as a protective shield in all species in which it occurs and differences in the form of the signum between species may be related to differences in the form of the harpes of the male.I wish to thank Dr J. Williamson for chromatography, Dr L. E. Stephen and Mr K. E. Broomfield for advice and assistance with the sectioning of the signa, Dr F. Peers for operating the Flame Photometer, Dr D. G. Godfrey for suggesting that the signa should be examined for calcium, and Mr W. Petana for taking the photomicrographs.I am indebted to Dr K. C. Willett, Director of the West African Institute for Trypanosomiasis Research, for criticism of the manuscript.
The tegument and associated structures of Haplometra cylindracea
Authors: Threadgold L. T. 
Published: June 2009

The tegument of Haplometra cylindracea is protoplasmic. It is organized on two levels, a surface syncytium (‘cuticle’ of the light microscopists) and tegumental cells which lie among the parenchymal cells below the muscle layers. The surface syncytium and tegumental cells are joined together by protoplasmic, tube-like, processes.The surface syncytium is covered apically and basally by a unit plasma membrane. It contains mitochondria, vacuoles, lipid bodies, spines with a crystalline structure and dense secretory bodies. This syncytium lies on a basement membrane and a thick, fibrous, interstitial layer. The connecting protoplasmic processes, which originate from the base of the syncytium, are vacuolated and have few inclusions but, as they approach the tegumental cells, they become progressively filled with cytoplasm, cell inclusions and dense bodies.The tegumental cells consist of individual areas of nucleated protoplasm, usually lying in groups. These cells contain dense secretory bodies, mitochondria, a few lipid droplets, crystalline inclusions, and Golgi complexes. The Golgi complexes and granular endoplasmic reticulum are jointly involved in the production of a dense, probably proteinaceous, secretory body. Some qualitative regional differences in tegumental ultrastructure are described.The tegument of Haplometra is compared with that of other species so far described and like them must be considered both a protective and a secretory epithelium.I should like to express my sincere thanks to the following: The Wellcome Trust and Science Research Council for grants to purchase an Akashi TRS 50 and and A.E.I. EM6B electron microscope respectively; the Royal Society for a personal grant to purchase a Reichert Ultramicrotome and a vacuum coating unit; the Wellcome Trust for a grant to employ a Research Associate.
Rapid and sensitive detection of Leishmania kinetoplast DNA from spleen and blood samples of kala-azar patients
Authors: Smyth A. J. , Ghosh A. , Hassan Md. Q. , Basu D. , De Bruijn M. H. L. , Adhya S. , Mallik K. K. , Barker D. C. 
Published: June 2009

SUMMARYFollowing sequence analysis of a Leishmania donovani kinetoplast DNA (kDNA) minicircle, we have developed synthetic oligonucleotides for use in the polymerase chain reaction (PCR). With these primers, we have amplified L. donovani kDNA from splenic aspirates and blood samples taken from kala-azar patients. Treatment of the samples for PCR requires only limited DNA purification by lysis in SDS, digestion with proteinase K, phenol extraction and ethanol precipitation of the resulting nucleic acid. We have obtained amplified product routinely with DNA prepared from the equivalent of 2·5–25 µl of splenic aspirate or of 50–500 µl of blood from infected patients. In dilution experiments a visible product has been obtained on amplification of DNA from the equivalent of 2·5 × 10−7 µl of splenic material. We therefore propose the amplification of L. donovani kDNA by PCR as a rapid and highly sensitive method for the diagnosis of kala-azar.
Studies on phosphatase systems in hepatopancreatic cells of the molluscan host of Echinoparyphium sp. and in the rediae and cercariae of this trematode
Authors: Cheng Thomas C. 
Published: June 2009

1. The distribution of acid and alkaline phosphatases in the hepatopancreatic cells of the molluscan host of Echinoparyphium sp. and in the redia and cercaria of this trematode has been studied.2. There is a heavier concentration of acid phosphatase in the hepatopancreas of infected snails than in uninfected snails.3. No acid phosphatase is present in the bodies of the rediae or cercariae but this enzyme is present in the contents of the redial caeca.4. Alkaline phosphatase activity is greater in the hepatopancreas of infected snails than in uninfected snails.5. Alkaline phosphatase is present in the tissues of the rediae and the cercariae, especially in the fully developed cercariae.6. It is suspected that the increase in acid and alkaline phosphatases in Helisoma trivolvis infected with Echinoparyphium redia is correlated with the breakdown of glycogen by the parasite.This research was made possible by Grants E-3443, E-3443C1, and AI 3443–03 from the Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service. The author is grateful to Mr Randall W. Snyder, Jr., School of Medicine, The University of Virginia, for technical assistance.
Effects of irradiation on surface carbohydrates of larvae ofSchistosoma mansoni
Authors: Wales A. , Fukumoto S.-I. , Otieno M. F. , Kusel J. R. 
Published: June 2009

SUMMARYUltra-violet irradiated larvae ofSchistosoma mansonistimulate high levels of resistance to challenge infection in experimental animals. In the experiments presented here, the binding patterns of antisera specific for the cercarial glycocalyx, and of various lectins, demonstrate that u.v. irradiation causes a pronounced modification of the carbohydrate antigens expressed at the surface of cercariae and newly transformed schistosomula.These alterations were dependent on the irradiation dose, and on the batch of cercariae used in each experiment. Our results strongly suggest that the changes in carbohydrate antigens consequent upon u.v. irradiation may be important in generating the enhanced immunogenicity of irradiated cercariae.