bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of DNA from some malarial parasites
Authors: Gutteridge W. E. , Trigg P. I. , Williamson D. H. 
Published: June 2009

The base compositions of DNA from some species of malarial parasite have been estimated by measurement of density in CsCl gradients and of thermal denaturation temperatures. Species from avian (Plasmodium gallinaceum) and rodent (P. bergheiandP. vinckei) hosts – often used as model systems in malarial studies – contain single DNA components with base compositions of about 20% G + C. By contrast, species from primate hosts (P. knowlesiandP. falciparum) contain major DNA components of about 40% G + C and minor ones of about 20% G + C. These differences could be reflexions of markedly different genomes within these two groups of the genusPlasmodium.Apart from differences in base composition, the physico-chemical properties of the main components of DNA from primate and rodent malarial parasites are very similar to those of DNA from mammalian cells. DNA from avian malarial parasites appears to have some unusual properties.One of us (P.I.T.) received financial assistance from the World Health Organization. We thank Dr F. Hawking and Dr J. Williamson for many helpful discussions, Dr W. H. G. Richards, Dr A. Voller and Dr D. C. Warhurst for the provision of some of the strains and Miss Jane Dunnett, Mrs A. C. Gutteridge and Mr T. Scott-Finnigan for technical assistance.
Studies on gut ultrastructure and digestive physiology in Rhabdias bufonis and R. sphaerocephala (Nematoda: Rhabditida)
Authors: Colam J. Barry 
Published: June 2009

Histological, histochemical and ultrastructural methods have been used to study gut structure and digestive physiology in the parasitic nematodes Rhabdias bufonis (Schrank, 1788) and R. sphaerocephala (Goodey, 1924). Both species are parasitic in the lungs of their amphibian hosts and feed entirely upon blood drawn from the lung capillaries.Three gland cells are present in the oesophagus, one in each sector. The two subventral ducts open, by way of ampullae, into the lumen of the oesophagus about a quarter of its length from the anterior end. The dorsal gland opens similarly into the base of the buccal capsule. It is suggested that the glands produce a B-esterase, in an histochemically inactive form in situ, which is responsible for haemolysis and the bulk of extracellular digestion. Only one cell type is present in the intestine and this is entirely absorptive in function.The major part of haemoglobin digestion is extracellular, partly by a process of contact digestion involving the B-esterase and acid phosphatase which are present in association with the microvilli. Haematin results from this process and is precipitated in the gut lumen. A smaller proportion of haemoglobin is taken up by the gut cells and is broken down intracellularly by lysosomes, originating in Golgi in the basal gastrodermis. These show endopeptidase activity and later acid phosphatase in some of the bodies of the lysosomal sequence and only at the light microscope level. The iron-containing pigment haemosiderin resulting from digestion is retained in the lysosome residues and forms the pigment granules in the gastrodermis. The products of extracellular digestion absorbed by the gastrodermis are synthetized into lipid by a lipase, probably produced by 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.
Opecoelid trematodes of marine fishes of India
Authors: Hafeezullah M. 
Published: June 2009

The present study includes five new and three known species of trematodes from marine fishes of India. Records of new hosts and new localities are given. The new species are: Plagioporus longicaudus, Opegaster paramacrorchis, Pseudopecoelina elongata, Pseudopecoeloides scomberi and Hamacreadium leiognathi. The known species are: Podocotyloides parupenei (Manter, 1963) Pritchard, 1966, Hamacreadium mutabile Linton, 1910 and H. krusadaiensis Gupta, 1956. Hamacreadium leiperi Gupta, 1956 is considered a synonym of H. mutabile.The author wishes to express his gratefulness to Dr Ather H. Siddiqi for his guidance and to Professor H. W. Manter of the University of Nebraska, U.S.A. for his valuable comments. The present study was financially supported by the Council of Scientific and Industrial Research, New Delhi.
A new species of Hoplopleura from Thailand, with notes and description of nymphal stages of Hoplopleura captiosa Johnson (Anoplura)
Authors: Kim Ke Chung 
Published: June 2009

The adult stage and nymph 2 of Hoplopleura johnsonae sp.nov. and the nymphal stages of H. captiosa Johnson are described. The morphology of Hoplopleura nymphs and the infraspecific variations of H. captiosa Johnson are discussed, and a key to the seven species of Hoplopleura Enderlein known in Thailand is also presented.I am grateful to Dr K. C. Emerson, Arlington, Virginia, and Dr Zofia Wegner, Gdansk-Wrzeszcz, Poland, for the loan of materials on which this work was based. I am also indebted to Dr Phyllis T. Johnson, University of California at Irvine, and Dr Edwin F. Cook, University of Minnesota, for their suggestions as to this species complex and reading the manuscript.
Experimental studies on the physiology of hatching of eggs ofAspiculuris tetrapteraSchulz (Oxyuridea: Nematoda)
Authors: Anya A. O. 
Published: June 2009

An experimental study of hatching in the oxyurid nematodeAspiculuris tetrapteraindicates that the major factors in the initiation of hatching are the pH and temperature of the environment and that the process is aerobic. Carbon dioxide and reducing agents do not appear to be as important factors in the hatching of eggs of this nematode as they are in the hatching of eggs of ascarids. It is suggested that the physiology of hatching in ascarids is not necessarily the typical nematode pattern.My grateful thanks are due to Dr P. Tate, Director of the Molteno Institute, and to Dr D. L. Lee for their encouragement and very helpful discussions on various aspects of this study.
The ultrastructure of the daughter sporocyst of Cercaria bucephalopsis haimaena Lacaze-Duthiers, 1854 (Digenea: Bucephalidae) from the edible cockle, Cardium edule L.
Authors: James B. L. , Bowers E. A. , Richards J. G. 
Published: June 2009

The body wall of the daughter sporocyst of Cercaria bucephalopsis haimaena Lacaze-Duthiers, 1854, is shown by the electron-microscope to consist of an external syncytial tegument, lying on a basement membrane, and an internal cellular subtegument, which surrounds a body cavity containing developing cercariae.The syncytial tegument has areas of dense cytoplasm alternating with sparse reticulate cytoplasm. The dense cytoplasm contains nuclei, a few mitochondria and secretory products which probably include a neutral mucopolysaccharide. This may be the precursor of the acid mucopolysaccharide in the sparse reticulate cytoplasm and on the surface of the daughter sporocyst.Nutrients are probably absorbed through the outer plasma membrane of the tegument, pass through the sparse reticulate cytoplasm in the middle region of the tegument, the inner plasma membrane and basement membrane into the subtegument.The ultrastructure of the tegument of adult and larval Digenea are compared.We would like to thank Dr Gwendolen Rees for allowing us to examine the electron-micrographs of Parorchis acanthus. We are also grateful to Professor E. W. Knight-Jones for the provision of excellent working facilities and to the Science Research Council, for a grant to one of us (E.A.B.) which made the work possible.
Histochemical observations on the occurrence of carbohydrates, lipids and enzymes in the daughter sporocyst of Cercaria bucephalopsis haimaena Lacaze-Duthiers, 1854 (Digenea: Bucephalidae).
Authors: James B. L. , Bowers E. A. 
Published: June 2009

The distribution of carbohydrates, lipids and enzymes in the daughter sporocyst and contained cercariae of Cercaria bucephalopsis haimaena Lacaze-Duthiers, 1854, is mapped and used as an indication of metabolism. It is concluded that host glucose, glycogen, fatty acids and neutral lipids are absorbed and pass through the syncytial tegument into the cellular sub-tegument. They are then either metabolized or passed into the body cavity and contained cercariae. Glucose seems to be either converted into glycogen and glycoproteins or metabolized anaerobically. The end products of anaerobic respiration are fatty acids and neutral lipids. These pass into the excretory system, which flushes them into the body cavity of the daughter sporocyst, from where they enter the body of the developing cercariae. In the cercariae they are deposited, together with host lipids, possibly as less toxic higher fatty acids or other stored lipids. The stored glycogen and lipids in the cercariae are probably utilized aerobically during the free-living existence. The transport of nutrients and excretory products across the cell membranes may be aided by alkaline phosphatase and esterase activity, as is the metabolism of carbohydrates and lipids. Acid mucopolysaccharide precursors appear to be synthesized in the dense cytoplasm of the mid-tegument of the daughter sporocyst and secreted into the host's visceral haemocoel. Acid phosphatase and esterase found in this region may be involved in the synthesis and also in the breakdown of complex incoming nutrients.We are grateful to Professor E. W. Knight-Jones for laboratory facilities and to the Science Research Council for a grant to one of us (E. A. B.) which made the work possible.
Studies on the haemocytic reaction ofGammarusspp., and its relationship toPolymorphus minutus(Acanthocephala)
Authors: Crompton D. W. T. 
Published: June 2009

The haemocytes ofGammarus, which are part of the environment ofP. minutes, have been found to react by encapsulation, against a variety of foreign bodies, wounded tissues and interspecific transplants. Cuticular wounds appear to present the most urgent stimulus to the haemocytes. The haemocytic reaction is not suppressed by X-irradiation. Differences in haemolymph salt concentration betweenG. pulexandG. duebenido not appear to be responsible for the failure of transplants of tissue fromG. pulextoG. duebeni.It is concluded that the haemocytic reaction ofGammarusis very similar in response and nature to that of insects.HealthyP. minutusdoes not stimulate the haemocytic reactions of its hosts, but wounded or damaged parasites are encapsulated. The capsule of connective tissue, which surrounds the parasite during its development in the haemocoele of the intermediate host, appears to be essential for the parasite's survival.I am most grateful to Dr P. Tate for helpful discussions, and Dr George Salt, F.R.S., for his advice and criticism of the manuscript. I also wish to thank Drs H. Laser and B. E. B. Moseley for irradiating the amphipods for me.
The fine structure of the trunk and praesoma wall ofAcanthocephalus ranae(Schrank, 1788), Lühe, 1911
Authors: Hammond R. A. 
Published: June 2009

The wall of the trunk, that of the praesoma, and the lemnisci ofAcanthocephalus ranaehave been studied by electron microscopy. Striations visible in sections of the body wall under the light microscope do not correspond with the ‘striped layer’ revealed by the electron microscope.A new region, the ‘canal layer’, has been described. This contains canals running into the body wall from cuticular pores.Structurally the wall of the trunk and that of the praesoma are similar. The lemnisci resemble the ‘inner layer’ of the praesoma wall. However, it is suggested that the wall of the trunk differs physiologically from that of the praesoma, and from the lemnisci. The possible roles of the wall of the praesoma and the lemnisci in fat excretion or uptake have been discussed.The body wall ofA. ranaehas been compared with that of the other acantho-cephalans studied with the electron microscope.Grateful acknowledgement is made to D.S.I.R. (now S.R.C.) for a research grant to the Department of Zoology for the purchase of a Huxley ultramicrotome, a vacuum coating unit, and an AEI EM 6 electron microscope.I am grateful to Dr D. A. Erasmus for reading and criticizing the manuscript, and to Mr T. Davies for valuable technical assistance.
On a monostome parasite of Indian domestic fowl with remarks on the genus Notocotylus Diesing, 1839
Authors: Nath Dharmendra , Pande B. P. 
Published: June 2009

Notocotylus is reported in Indian domestic fowl and the specimen assigned to the species N. attenuatus. The literature on this monostome genus is briefly reviewed and need for an examination of type specimens of some of its species is stressed.Thanks are due to the Principal of the college for facilities provided and to the head of the Zoology Department, Lucknow University, for loan of some literature.
Studies on two new coccidia from the Venezuelan lizardCnemidophorus lemniscatus lemniscatus: Hoarella garnhamigen.nov., sp.nov. andEimeria flaviviridis americanasubsp.nov.
Authors: de Peraza Lucila Arcay 
Published: June 2009

This work contains the description of two new Coccidia parasitic in the South American lizardCnemidophorus lemniscatus lemniscatus. One is identified asEimeria flaviviridis americanasubsp.nov., which is described and discussed in relation to the other species recorded from sauria. The other isHoarella garnhamigen.nov., sp.nov., whose position in the family Eimeriidae necessitated a revision of the classification of the Coccidia Eimeriidae.I wish to acknowledge the help and encouragement I received from Professor P. C. C. Garnham, in whose department this work was carried out. My thanks are also due to Dr Cecil Hoare for his private communications and assistance in the interpretation of histological specimens. The author is grateful for co-operation of the School's Photograph Staff and to members of the staff of the Department of Parasitology, especially to Mr P. E. Nesbitt for his valuable sections. Finally, the author is indebted to the Consejo de Desarrollo Cientifico y Humanístico de la Universidad Central, Caracas, for their assistance in the form of a scholarship during the tenure of which this work was produced.
Electron-microscope studies of Fasciola hepatica III. Further observations on the tegument and associated structures
Authors: Threadgold L. T. 
Published: June 2009

Additional ultrastructural features of the tegument of Fasciola hepatica, after glutaraldehyde fixation and high resolution, have been observed.Two distinct types of tegumental cells are shown to be present, the type 1 cell having been previously described. Details of the fine structure of the nucleus, mitochondria, endoplasmic reticulum and Golgi complex of the type 2 cell are given. The type 2 cell is characterized by biconcave secretory bodies derived from the Golgi complex and the latter is intimately related to the granular endoplasmic reticulum, from which it is derived by blebbing. The type 2 cells are connected by protoplasmic tubes to the same surface syncytium as type 1 cells.These new findings of the structure of the tegument of Fasciola are compared with previous reports on the ultrastructure of the tegument in other flukes.I should like to express my sincere thanks to the following: the Wellcome Trust and S.R.C. for grants to purchase an Akashi TRS 50 and an A.E.I. E.M. 6B electron microscope respectively; the Royal Society for a personal grant to purchase a Reichert Ultramicrotome and a vacuum coating unit.My thanks are also due to Mr W. Ferguson for photographic skill and to Mr A. Lyness for technical assistance and microscope maintenance, and my Research Associate, Mrs S. S. E. Dermott, for expert electron-microscopy.
Observations on the nutrition of digenetic trematodes
Authors: Halton D. W. 
Published: June 2009

Both histological and histochemical studies have been made of the food, mode of feeding, gut cell structure and digestive sequences in a selected number of digenetic trematodes.The species investigated range from gut-dwelling trematodes feeding on the superficial epithelial tissues and associated mucoid secretions of the host to those forms living within the respiratory and circulatory system and feeding exclusively on blood.The mode of feeding is suctorial, brought about by the muscular pharynx and normal attachment process of the oral sucker. In one case there is evidence that this purely mechanical process is supplemented with enzymic secretions produced by the trematode which have a histolytic effect upon host tissues.On the basis of gut cell structure the species investigated are divided into those with cells and associated microvilli that vary in size and appearance so that the gastrodermal border is irregular in outline, and those with a gastrodermis comprising regular cuboidal or columnar cells bearing microvilli organized into a striated border. There is evidence to suggest that this difference in gut cell structure reflects differences in digestion. In all cases, gland cells are absent from the gastrodermis which is capable of both secretory and absorptive functions.Digestion is predominantly an extracellular process, but the exact sequence varies according to the nature of the food ingested and different degrees of adaptation are shown by the trematodes to the blood-feeding habit. The tissue-feeding species show less modification.I wish to thank Dr J. B. Jennings for helpful discussion and advice throughout the course of this work. The study was undertaken during the tenure of a Studentship from the Department of Scientific and Industrial Research.
Observations on Transversotrema patialensis (Soparkar, 1924) (Trematoda) from Waltair, Andhra Pradesh (India)
Authors: Rao K. Hanumantha , Ganapati P. N. 
Published: June 2009

Cercaria patialensis Soparkar, 1924, emerging from the snail Melanoides tuberculatus (Müller) has been encountered at Waltair. The cercariae begin to emerge from the snail at dusk and continue to do so during the period of darkness.Stages resembling the adult but without the development of eggs have been encountered in nature on the fresh water fishes Panchax panchax (Ham. & Buch.) and Esomus danricus (Bleeker). These stages have also been raised experimentally by exposing P. panchax, E. danricus and fingerlings of Catla catla Ham. & Buch. to the cercariae.The cercaria is referable to the genus Transversotrema Witenberg, 1944.It is suggested that there may not be a metacercarial stage in the life-cycle of Transversotrema spp.
On the biology and morphology of Echinococcus granulosus (Batsch, 1786) of buffalo–dog origin
Authors: Gill Hardev Singh , Rao B. Venkateswara 
Published: June 2009

The present material of buffalo–dog origin could not be transmitted to the laboratory animals, such as white rats, white mice, rabbits, golden hamsters, guinea-pigs and chicks.Secondary development took place only in mice.The strobilar phase was infective to a cat but did not show sexual differentiation even at 30 days, and worms were further observed to be at a degenerative stage.The buffalo was highly suited to the perpetuation of the parasite, forming larger cysts and massive production of scoleces; nearly 90% of the cysts were fertile.The strobila had mostly two segments and not more than three.The number and distribution of testes were more posterior to the genital pore and were also observed posterior to the vitellaria, occasionally.The position of the genital pore in the gravid as well as mature segments was both anterior and posterior but with an average of 52.8%.Uterine sacculations were observed to range from 28 to 54.Echinococcus material of buffalo–dog origin does not appear to fall into a definite ‘subspecies’ pattern. It is suggested that it be merely recognized as a further ‘mutant’, the existence of which can be accounted for on theoretical grounds.The authors are thankful to the Director, Indian Veterinary Research Institute, and to Dr H. D. Srivastava, Head of Division of Parasitology, I.V.R.I., for providing the necessary laboratory facilities.
Some stylet cercariae and a microphallid type in British freshwater molluscs
Authors: Pike Alan W. 
Published: June 2009

Cercaria helvetica XXXIII Dubois and the cercaria of Sphaerostoma bramae (Müll.) are redescribed and their metacercariae, which occur in various invertebrates, are described. Additional observations are made on C. parvus Khan and C. tarda Khan and their metacercariae, occurring mainly in arthropods, are described. C. wentloogensis sp.nov. has four pairs of penetration glands, a slender, thickened stylet 0·03 mm long and the flame-cell formula2[(2 + 2 + 2) + (2 + 2 + 2)].C. rumniensis sp.nov. has four pairs of penetration glands lying dorsally to the acetabulum, a slender thickened stylet 0·03 mm long and at least 20 flame cells arranged in pairs. C. octoglandulata sp.nov. is a virgulate species with four pairs of penetration glands, a partially thickened stylet 0·029–0·032 mm long and the flame-cell formula 2[(3 + 3 + 3) + (3 + 3 + 3)]. Each of these new species develops in sporocysts in the digestive gland of the prosobranch mollusc Bithynia tentaculata. A cercaria occurring in the digestive gland of B. tentaculata and assigned to the Microphallidae on the structure of its metacercaria is considered to encyst in the digestive gland without emerging. It bears no stylet or penetration glands and the cysts occur in the snail in exceedingly large numbers.All of these cercariae were found in freshwater molluscs collected at the Wentloog level near Cardiff, South Wales.
Observations on the free-living stages of the stomach worm Haemonchus contortus
Authors: Rose J. H. 
Published: June 2009

Outdoor observations were made on the rate of development of the free-living stages of H. contortus at different times of the year, and on the migratory activities and longevity of the larvae in faeces, on herbage and in soil.The effects of temperature and humidity on the survival and development of eggs and larvae, both in faeces and when separated from the faeces, were studied in the laboratory.The results of these observations are discussed in relation to the heavy mortality of the free-living stages of H. contortus and to the transmission of infection in the field.
Morphological and histochemical observations onPolymorphus minutus(Goeze, 1782), with special reference to the body wall
Authors: Crompton D. W. T. 
Published: June 2009

1. Certain aspects of the general morphology ofPolymorphus minutusare described together with a detailed description of the body wall.2. An additional layer of the body wall, the epicuticle, has been demonstrated. It appears to consist of acid mucopolysaccharide and may have a function of protecting the parasite from the enzymes of its host.3. A histochemical investigation has been made of the layers of the body wall and it is concluded that lipoprotein is one of the main structural components.4. The distribution of the activity of the two enzymes, non-specific esterase and alkaline phosphatase, has been studied throughout the animal and the activity of a third enzyme, leucine aminopeptidase, has been detected in the body wall.5. It is suggested that all the layers of the body wall, with the exception of the cuticle and epicuticle, are of metabolic importance. The striped layer may be connected with absorption and the felt and radial layers may be involved in the further metabolism of absorbed compounds.6. The results obtained are used to formulate a possible structure of the surface of the parasite which would facilitate the absorption of nutrient substances through the body wall.I am grateful to Dr P. Tate for advice and encouragement during this work, Dr R. J. Tatchell for helpful discussions, and Dr D. L. Lee for criticising the manuscript and Mr T. M. Warwick, Department of Zoology, University of Edinburgh for providing material.