bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the transmission, biology and morphology of Echinococcus granulosus equinus, a new subspecies of hydatid tapeworm in horses in Great Britain
Authors: Williams R. J. , Sweatman G. K. 
Published: June 2009

1. A 12·8% incidence of hydatid infections occurred in 709 horses examined in England. By contrast, hydatid cysts do not occur in horses in New Zealand where Echinococcus granulosus granulosus is common in sheep, cattle and swine.2. Experimentally, scolices from hydatid cysts from English horses reached a gravid state in laboratory dogs. It was not possible to infect horses with E. g. granulosus of sheep-dog origin, and only one of two sheep became infected with two cysts following the ingestion of eggs of English horse-dog origin.3. Our observations, together with those of others on secondary hydatid cyst formation, indicate that the two types are not only biologically but morphologically distinct.4. In the horse-dog worms, the cirrus sac tilts anteriorly at an acute angle; the testes (about 35) are distributed throughout the proglottid with two or three rows posterior to the vitelline gland, and persist in proglottids when some mature eggs are present; the average length of the rostellar hooks is greater than in E. g. granulosus.5. It is proposed that the horse-dog material be named E. g. equinus subsp. nov.6. Rostellar hooks from cysts in British cattle resembled morphologically those from horses, while those from a British sheep and from man were like the hooks from hydatid cysts in man and livestock in New Zealand.7. A red deer, hedgehog and European rabbit were not infected artificially following the ingestion of eggs of E. g. equinus.Mr J. T. Briggs, Chief Public Health Inspector, Public Health Department, Bently, Doncaster, England, was responsible for the inspection of the British horses reported in this paper. We are indebted to Mr Briggs for this courtesy and for sending us fresh hydatid cysts from horses for experimental purposes. Mr N. Aitken was responsible for maintaining the experimental horses in an area of New Zealand known to be free of E. granulosus. Our thanks are also due to Messrs G. D. Page, D. V. Weston, Miss L. A. Duncan and Mrs B. R. Clarke for their able technical assistance.
Effect of temperature on the development of free-living adults of Strongyloides papillosus (Wedl, 1856)
Authors: Premvati  
Published: June 2009

Strongyloides papillosus is found to be very common in the Lucknow area where 90% of the sheep are infected. The life-cycle is predominantly indirect, or heterogonic. The development of mature free-living adults takes place between 20° and 37° C., and 34° C. is the optimum temperature. At a temperature of 25° C., the percentage of free-living adults is 60–65 in summer (March to November) and practically 100 in winter (December to February). Immature females can develop at 40° C. in summer, but not in winter, under laboratory conditions.Inhibition experiments in a hot oven incubator with varying percentages of humidity, and in a humidity chamber incubator with constant 100% humidity, maintained at temperatures varying from 40° to 50° C., show that in the humidity chamber incubator mature free-living adults develop at 34° C. after incubation for 12 hr. at 40° C., after 4 hr. at 42° C., after 2 hr. at 45° C. and after 15 min. at 50° C. The hot oven incubator allows mature free-living adults to develop at 34° C. after 8 hr. at 40° C., after 2 hr. at 42° C., after 1 hr. at 45° C. and after 15 min. at 50° C.
The infestation of the redfishSebastes marinus(L.) andS. mentellaTravin (Scleroparei: Scorpaenidae) by the copepodsPeniculus clavatus(Müller),Sphyrion lumpi(Krøyer) andChondracanthopsis nodosus(Müller) in the eastern North Atlantic
Authors: Williams I. C. 
Published: June 2009

1. An account is given of the intensity and incidence of infestation of the scorpaenid redfish,Sebastes marinusandS. mentella, by the parasitic copepodsPeniculus clavatus, Sphyrion lumpiandChondracanthopsis nodosuson three fishing grounds in the eastern North Atlantic, namely Iceland, Bear Island and the Barents Sea.2.Peniculus clavatuswas found to be a rare parasite on both species of redfish in the eastern North Atlantic. Adult female parasites were found during the months from September to February only; they were usually attached to the pelvic or dorsal fins of the host causing little damage.3.Sphyrion lumpiwas found to be a comparatively rare parasite on the deep-waterSebastes mentellathroughout the eastern North Atlantic but it was found onS. marinusin the vicinity of Bear Island only. It seems justifiable to regard the Bear Island grounds as a centre of abundance ofSphyrion lumpiin the eastern North Atlantic. Adult femaleS. lumpitended to infest medium-sized redfish more often than smaller or larger fish.4. The infestation ofSebastes marinusandS. mentellabyChondracanthopsis nodosushas been examined in some detail and attention directed to the influence on infestation of the host species, geographical distribution, body length, age and sex of the host, and seasonal variations. The distribution of femaleC. nodosuswithin the gill chamber of the two species of redfish is described; it appears to be related to the need of the parasite to secure a protected and spatially limited habitat out of the mainstream of the ventilation current through the gill chamber.5. The ecological relationships betweenSebastes marinusandS. mentellaand the three species of parasitic copepod are described together with the possibility of using these and other parasites as indicators of the host's mode of life. It is concluded thatChondracanthopsis nodosusandSphyrion lumpimerit more detailed and extensive study as possible parasitological indicators of different stocks of redfish.I wish to express my thanks to Messrs Jackson Mills Ltd., Fish Merchants and Curers, Hull, and to the Officer-in-Charge, D.S.I.R., Humber Laboratory, Hull, for their generous assistance in making redfish available for examination. I am also most grateful to Miss E. C. Howard, Librarian, Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, for her invaluable assistance in providing certain otherwise unobtainable references in the literature.
Effects of Eubothrium salvelini (Cestoda) on the behaviour of Cyclops vernalis (Copepoda) and its susceptibility to fish predators
Authors: Poulin R. , Curtis M. A. , Rau M. E. 
Published: June 2009

SUMMARYTo facilitate the completion of their life-cycle, many helminth parasites have evolved the ability to manipulate the behaviour of their intermediate host in order to make it more likely to be eaten by the parasite's definitive host. Here, we determined whether the cestode Eubothrium salvelini modifies the behaviour of its intermediate host, the copepod Cyclops vernalis, and makes it more susceptible to predation by brook trout, Salvelinus fontinalis, the parasite's final host. Following the experimental infection of copepods, the spontaneous activity of infected and control subjects was quantified weekly. In addition, we regularly quantified predation by individual brook trout fry on known numbers of infected and control copepods. At approximately the time when the cestode larvae became infective to fish (2–3 weeks following infection), the infected copepods started to swim more actively than uninfected controls. Also at that time, infected individuals became more likely to be captured by fish than uninfected ones. Copepod size and intensity of infection had no significant effect on their behaviour or their risk of being eaten by fish. Thus cestode- induced changes in copepod swimming activity can lead to infected copepods becoming highly vulnerable to fish predators, and may have resulted from selection on the parasite to increase its transmission success
Biosynthesis and glycosylation of serine/threonine-rich secreted proteins fromToxocara canislarvae
Authors: Page A. P. , Maizels R. M. 
Published: June 2009

SUMMARYToxocara canisinfective stage larvae continually produce excretory–secretory (TES) glycoproteins in long-termin vitroculture. The kinetics of synthesis and secretion were studied by metabolic labelling with radioactive [35S]methionine, [14C]serine and [14C]threonine. Maximal incorporation rates required overnight pre-incubation of parasites in medium depleted of the appropriate amino acid. Larvae rapidly incorporated isotope into their somatic tissues, but there was a minimum delay of 10 h before secretion of labelled antigens. Labelling with [14C]serine and [14C]threonine demonstrated a relative abundance of these amino acids in the major surface/secreted glycoproteins of this nematode (TES-32 and 120). Pulse-chase experiments suggested that TES-120 may be derived from a 58 kDa precursor, reflecting extensive post-translational glycosylation. Inhibition ofN-glycosylation with tunicamycin and digestion withN-glycanase provided evidence ofN-glycosylation in the lower molecular weight ES components (TES-32, 55 and 70). These agents had no effect on the higher molecular weight components (TES-120 and 400) implying that for these molecules glycosylation is predominantlyO-linked. The largest ES component (TES-400) was unusual, in incorporating serine and threonine but not methionine, and by exhibiting increased apparent molecular weight following pronase digestion; it is suggested that this molecule is a proteoglycan.
The role of nematode parasites in Soay sheep (Ovis ariesL.) mortality during a population crash
Authors: Gulland F. M. D. 
Published: June 2009

SUMMARYIn early 1989, two-thirds of the Soay sheep population on St Kilda died over 12 weeks. Post-mortem examinations revealed emaciated carcasses and considerable nematode burdens, with protein-energy malnutrition as the probable cause of death. Haematological and blood biochemical changes in the sheep, as well as fecundity of gastrointestinal nematodes, suggested the hosts were immunosuppressed. In parallel, laboratory experiments in which Soay sheep on a high plane of nutrition were artificially infected withOstertagia circumcincta, showed no clinical signs or mortality when supporting worm burdens similar to those recorded in dead sheep on St Kilda. Anthelmintic treatment of a group of animals increased daily survival rates in ewes and male lambs, although treated animals became re-infected as the ‘crash’ progressed. It is suggested that parasites contribute to mortality in malnourished hosts, exacerbating the effects of food shortage.
Neuropeptide F (Moniezia expansa): localization and characterization using specific antisera
Authors: Maule A. G. , Shaw C. , Halton D. W. , Brennan G. P. , Johnston C. F. , Moore S. 
Published: June 2009

SUMMARYImmunocytochemical techniques used in conjunction with confocal scanning laser microscopy (CSLM) and electron microscopy have been used to demonstrate, for the first time, the distribution of the parasitic platyhelminth neuropeptide, neuropeptide F (NPF) in the cestode, Moniezia expansa. Antisera were raised to intact NPF(1–39) and to the C-terminal decapeptide of NPF(30–39). These antisera were characterized and validated for use in both immunocytochemistry and radioimmunoassay (RIA). NPF immunoreactivity (IR) was detected using both antisera throughout all of the major components of the central and peripheral nervous systems of the worm. The pattern of NPF-IR was found to mirror the IR obtained using a C-terminally directed pancreatic polypeptide (PP) antiserum and FMRFamide antisera; blocking studies using these antisera revealed that FMRFamide and PP antisera cross-react with NPF(M. expansa). RIA of acid-alcohol extracts of the worm measured 114 ng/g using the C-terminal NPF antiserum and 56 ng/g using the whole-molecule-directed antiserum. While the C-terminally-directed NPF antiserum cross-reacts with NPF-related peptides from other invertebrates, the whole-molecule-directed NPF antiserum is specific for NPF(M. expansa). The C-terminal NPF antiserum has potential for use in the identification and purification of NPF analogues from other platyhelminth parasites.
Dynamic interaction between CD4+ T cells and parasitic helminths: mathematical models of heterogeneity in outcome
Authors: Schweitzer A. N. , Anderson R. M. 
Published: June 2009

SUMMARYPotential mechanisms of immunoregulation have been investigated for the capacity to generate heterogeneity in the outcome of infection with helminth parasites. We have developed a mathematical model of the interaction between T cell and parasite populations, based on the assumption that activation of a Th1 CD4+ T cell response is required for host resistance. Antigen dose-dependent inhibition of Th1 cell proliferation generates heterogeneity in the outcome of host response to infection, with relatively low levels of exposure inducing resistance, and high levels of exposure associated with host susceptibility. Heterogeneity is additionally predicted in the duration of infection before individuals of the resistant class clear infection, with infection becoming more prolonged as the level of exposure rises. Similar categories of response are predicted if an alternative regulatory mechanism, that of interferon γ-regulated control of Th1 cell differentiation, is substituted into the model. However, the relationship between level of exposure and duration of infection is reversed. Results are discussed in the context of how these simple models of parasite–immune system interactions might be used to make predictions concerning specific examples of parasitic infection.
The novel hydroxynaphthoquinone 566C80 inhibits the development of liver stages ofPlasmodium bergheiculturedin vitro
Authors: Davies C. S. , Pudney M. , Nicholas J. C. , Sinden R. E. 
Published: June 2009

SUMMARYThe causal prophylactic activity of the novel hydroxynaphthoquinone, S66C80, was assessed against the exo-erythrocytic (EE) stages ofPlasmodium bergheicultured in the human hepatoma cell line, HepG2. 566C80 was found to be highly active as an inhibitor of EE development and was more active than the established causal prophylactic pyrimethamine. A 566C80 concentration of 1·85 × 10−9M, added 3 h after sporozoite invasion, reduced the numbers of EE forms visible at 48 h by 50%, while the equivalent concentration of pyrimethamine was 1·95 × 10−8M.
A study of carbohydrate metabolism in the eggs (oncospheres) of the tapeworm,Hymenolepis diminuta, with special reference to glucose
Authors: Pappas P. W. , Durka G. M. 
Published: June 2009

SUMMARYWhen incubatedin vitrofor 24 h, intact eggs, chemically shelled eggs (obtained by treating intact eggs with NaOCl), activated larvae (eggs in which the outer shell and inner envelope were removed), and oncospheres (activated larvae treated with papain to remove the embryophore) absorb and metabolize radioactive glucose. Intact eggs, which are covered by the impermeable shell, absorb only small amounts of exogenous radioactive glucose, while chemically shelled eggs, activated larvae, and oncospheres absorb much larger amounts. Only very small amounts of the exogenous glucose are incorporated into the ethanol-precipitable carbohydrate fraction (which would include glycogen) by any of the preparations of eggs/larvae. However, the glucose is incorporated into higher molecular weight end-products that are liberated into the incubation medium. There is a temporal shift in the ability of activated larvae and oncospheres to metabolize exogenous glucose. Activated larvae and oncospheres absorb but do not metabolize glucose during the first 8 h post-activation. Between 8 and 16 h post-activation, however, virtually all of the absorbed glucose is metabolized into higher molecular weight end-products that are liberated into the incubation media. This temporal shift suggests that activation of oncospheres and cysticercoid morphogenesis are accompanied by distinct changes in carbohydrate metabolism.
In vitroisolation and characterization of aNeospora sp. from aborted bovine foetuses
Authors: Conrad P. A. , Barr B. C. , Sverlow K. W. , Anderson M. , Daft B. , Kinde H. , Dubey J. P. , Munson L. , Ardans A. 
Published: June 2009

SUMMARYANeospora sp. was isolated from the brains of two aborted bovine foetuses and grown continuouslyin vitroin bovine cell cultures. A comparison of the antigenic reactivity ofin vitrocultivated tachyzoites with polyclonal antisera toNeospora caninum, Hammondia hammondi or Toxoplasma gondiirevealed that the bovine protozoal isolates were similar toN. caninumand antigenically distinct fromT. gondii. Tachyzoites of both bovine isolates had similar ultrastructural features, including an apical polar ring, conoid, electron-dense rhoptries and micronemes. The orientation of the micronemes, presence of micropores and a large number of electron-dense granules in the posterior portion of the bovine isolate tachyzoites differed from previous descriptions ofN. caninum in vivo. Tachyzoites of the bovine isolates were ultrastructurally more similar toin vitrocultivatedN. caninumtachyzoites than to tachyzoites ofT. gondiiorH. hammondi. The antigenic and ultrastructural similarities betweenN. caninumand the protozoal parasites isolated from aborted bovine foetuses in this study support the proposition that these parasites belong to the genusNeospora.
Nutrition support and the human immunodeficiency virus (HIV)
Authors: Bell S. J. , Mascioli E. A. , Forse R. A. , Bistrian B. R. 
Published: June 2009

SUMMARYNutritional support of patients with HIV or acquired immune deficiency syndrome (AIDS) has many similarities to other disease states in that the same nutritional products and techniques are used. Some patients with HIV, and many with AIDS without secondary infection, experience a metabolicmilieusimilar to patients with cancer cachexia. In providing dietary counselling to the HIV patient, we encounter many of the obstacles that must be overcome to improve nutrition in cancer: anorexia, gastrointestinal discomfort, lethargy, and poor nutrient utilization, which limit the ability for nutritional repletion. When a secondary infection is superimposed on HIV, patients resemble more highly catabolic trauma patients or patients in the intensive care unit (ICU), where, despite aggressive efforts to feed, there is usually a net nitrogen wasting leading to the more rapid development of cachexia. However, even in this setting, feeding will limit substantially net catabolism when compared to total starvation. Because the nutritional needs of HIV patients vary greatly, individual strategies have to be designed as the patient moves through the stages of disease. Patients are generally able to consume adequate nutrition either as regular food or dietary supplements during the latency period of viral replication. Once secondary infections become prevalent, artificial diets administered by tube or by vein may be required during the period of active secondary infections, with dietary supplements often helpful during more quiescent periods. Patients with HIV are among the most challenging for clinicians providing nutritional support. Knowledge from treatment of patients with other diseases may be useful, but more data must be gathered on the unique aspects of aetiology and treatment of the anorexia, malabsorption, and ultimate wasting associated with AIDS.
Energy requirements in human pregnancy, in human nutrition and parasitic infection
Authors: Durnin J. V. G. A. 
Published: June 2009

SUMMARYThe energy requirement of pregnancy reflects a problem which contains a great deal of uncertainty. To supply the theoretical energy needs for the increases in maternal and foetal tissues and to cover the elevated basal metabolic rate involves an amount equivalent to an extra 250–300 kcal/day on average, but in real-life situations there is seldom a rise in dietary energy of a comparable quantity. Data from co-ordinated longitudinal studies in four countries, together with results from other published papers, show energy intakes increasing by only 100–150 kcal/day, and only in the third trimester. Although it is difficult to demonstrate, the probability is that there are energy savings in reduced physical activity which compensate for the larger energy needs.
Biochemistry and molecular genetics of Leishmania glucose transporters
Authors: Langford C. K. , Burchmore R. J. S. , Hart D. T. , Wagner W. , Landfear S. M. 
Published: June 2009

SUMMARYGlucose is utilized as a significant source of metabolic energy by Leishmania parasites. This sugar is accumulated by the parasite via a specific carrier-mediated transport system located in the parasite membrane. Parasites may also contain another transporter that shuttles glucose between the cytoplasm and the glycosome, a membrane-bound organelle where the early steps of glycolysis occur. The transport systems of both the insect stage promastigotes and the intracellular amastigotes have been characterized and shown to have kinetic properties that are consistent with the different physio-logical environments of the insect gut and the macrophage phagolysosome. Several genes have been cloned from Leishmania species which encode proteins with substantial sequence similarity to glucose transporters from mammals and lower eukaryotes. Two of these genes are expressed preferentially in the promastigote stage of the life cycle, where glucose is more readily available and more rapidly transported and metabolized than in the intracellular amastigotes. One of these two developmentally-regulated genes has been functionally expressed in Xenopus oocytes and shown to encode a glucose transporter. A third gene encodes a protein that is also a member of the glucose transporter family on the basis of sequence similarity and proposed secondary structure. However, the significant differences between this protein and the other two suggest that it is likely to transport a different substrate. Functional expression will be required to define the specific biochemical role of each gene within the parasite.
Evolutionary pressures in the spread and persistence of infectious agents in vertebrate populations
Authors: Anderson R. M. 
Published: June 2009

SUMMARYInfectious agents have considerable potential to regulate or constrain the population growth of vertebrate hosts in natural habitats. A broad theoretical framework provides many insights into how the biology of the parasite and the demography of the host interact to determine this impact. It may manifest itself as a steady influence over time via stable endemic infection or in a recurrent epidemic fashion, sometimes with unpredictable intervals between epidemics depending on the generation time of the pathogen (time from infection to recovery or host death), its ability to induce lasting immunity and the population growth rate of the host species. Building on these notions, the paper focuses on recent work on the population dynamics of genetically variable pathogen populations and examines the factors that determine the evolution of virulence and the maintenance of genetic diversity in both host and pathogen. Recent research extends conventional theoretical templates to include population genetic elements and the within-host dynamics of the parasite and its interaction with the vertebrate immune system.