bluuebunny/crossref_metadata_2025_split huggingface dataset:
An experimental and theoretical study of the dynamics of a mouse – nematode (Heligmosomoides polygyrus) interaction
Authors: Scott M. E. 
Published: June 2009

SUMMARYThe population dynamics of outbred laboratory mice in indoor enclosures in the absence and presence of a naturally transmitted direct life-cycle nematode Heligmosomoides polygyrus Dujardin 1845 were reported previously. This manuscript presents further information on the age and sex structure of the populations, results of experiments designed to estimate the density-dependent effect of the parasite on host survival and reproduction, and a mathematical model of both uninfected and infected mouse populations. In the uninfected mouse population, survival of female mice was age- and density-independent, survival of male mice was age-dependent and density-independent, and recruitment was density-dependent. Independent experiments revealed that the parasite had no density-dependent effect on mouse reproduction, but had density-dependent effects on both acute and chronic survival of mice. An age-structured Leslie matrix model captured the exponential growth and plateau of the uninfected mouse population. Modification of the model to incorporate the effects of the parasite provided a good fit to the data from the infected populations, supporting the hypothesis that density-dependent effects of the parasite on host survival could lead to regulation of host abundance.
Carbohydrate reserves and infectivity in Trichinella spiralis isolated from carrion
Authors: Raines Karen M. , Stewart G. L. 
Published: June 2009

SUMMARYTrichinous mice were killed and their carcasses maintained at room temperature or subzero temperatures for varying lengths of time. Some worm parameters were measured after direct isolation from carcasses while others were measured following passage through a second round of hosts. Glycogen and trehalose levels in infective 1st-stage larvae (L1) isolated directly from carcasses maintained at room temperature were significantly less than controls (day 0) after day 4 post-kill (p.k.). By day 21 p.k. among L1 isolated directly from mouse carcasses those observed coiled or moving had decreased by around 20% compared to day 0 p.k. The percentage of L1 isolated from carcasses on several days p.k., used to infect mice and recovered as pre-adult worms declined significantly after they had remained in carcasses for 14 days. Only 2·6% of muscle larvae isolated from carcasses on day 21 p.k. and used to infect mice were recoverable as pre-adults. Pre-adult worms raised in mice infected with larvae from day 7 carcasses had about 50% less glycogen than worms raised in mice infected with larvae isolated from fresh carcasses (day 0 p.k.). The fecundity in vitro of adult worms isolated from mice on day 7 following infection with infective L1 larvae maintained in carcasses held at room temperature for 0–16 days declined only when adult worms developed from larvae recovered from carcasses at 3 days following host death. Following 24 h at temperatures below freezing, infectivity of L1 larvae isolated from frozen carcasses was reduced by 97%. Carbohydrate levels remained high in larvae from carcasses frozen for up to 4 days.
Polychromophilus murinus: a malarial parasite of bats: life-history and ultrastructural studies
Authors: Gardner R. A. , Molyneux D. H. 
Published: June 2009

SUMMARYPolychromophilus murinus, a malaria parasite of Chiroptera is reported from Myotis daubentoni in England. The vector was suspected to be the ectoparasitic Nycteribiid fly, Nycteribia kolenatii. N. kolenatii collected from wild-caught M. daubentoni were found to have oocysts on the midgut and sporozoites in the salivary glands. Wild-caught N. kolenatii were maintained on two wild-caught M. daubentoni harbouring heavy (patent) infections of P. murinus; both oocysts and sporozoites were found in these flies. The mature oocysts measured 52–71 μm in diameter. Sporozoites were straight or slightly crescentic and had a mean length of 7·4 μm. Electron microscopy of immature and mature oocysts revealed a morphology similar to that of malaria parasites. Sporozoites were also similar in structure to Plasmodium sporozoites and were found in the epithelial cells of the salivary gland and within the lumen; a cytostome was present and transverse sections revealed 21 microtubules arranged evenly around the periphery. Sporozoites were observed within the basement membrane of the salivary gland of N. kolenatii; such sporozoites appeared to be penetrating the gland, a process hitherto not described in malaria parasites. Rickettsia-like bodies were found within the cytoplasm of the epithelial cells of the salivary gland. Exflagellation of microgametocytes was achieved. An ultrastructural study of the gametocytes revealed a structure similar to that described in other Haemoproteidae. A common feature of infected erythrocytes was a projecting erythrocyte membrane. Attempts to find schizogony in impression smears and sections of tissues of two infected M. daubentoni were not successful.
A genetic analysis of reproduction in Strongyloides ratti
Authors: Viney M. E. 
Published: June 2009

SUMMARYStrongyloides ratti has a complex life-cycle with two adult generations, one free-living and dioecious and one parasitic and female only. The parasitic females reproduce by parthenogenesis, but it is unclear whether this is mitotic or meiotic in nature. This question has been addressed genetically by analysing the progeny of parasitic females that were heterozygous at an actin locus for evidence of allelic segregation. Such progeny were similarly heterozygous showing that segregation had not occurred. It was therefore concluded that reproduction in the parasitic female of S. ratti is functionally mitotic.
Parasites of wild brown rats (Rattus norvegicus) on UK farms
Authors: Webster J. P. , Macdonald D. W. 
Published: June 2009

SUMMARYWild brown rats (Rattus norvegiens) from 11 rural UK farmsteads were found to carry 13 zoonotic and 10 non-zoonotic parasitic species, many of which (e.g.Cryptosporidium, Pasteurella, Listeria, Yersinia, CoxiellaandHantavirus) have rarely or never been previously investigated for wild rats. The study suggests that wild brown rats, serving as vectors of disease, represent a serious risk to the health of humans and domestic animals in the UK.
Susceptibility of brook charr,Salvelinus fontinalisto the pathogenic haemoflagellate,Cryptobia salmositica, and the inheritance of innate resistance by progenies of resistant fish
Authors: Forward G. M. , Ferguson M. M. , Woo P. K. T. 
Published: June 2009

SUMMARYEighty-seven of 175 laboratory raised F1 generation brook charr (Salvelinus fontinalis) were resistant to experimentalCryptobia salmositicainfection. Susceptibility to the pathogen was not related to age nor to route of infection. Plasma of resistant charr lysed the parasite underin vitroconditions while those of susceptible fish did not. Sperm from 4 susceptible and 4 resistant male charr, from 8 F1 families, were used to fertilize eggs from 2 hatchery raised susceptible charr. Susceptibility of progenies (F2 families) was determined 4 weeks after inoculation of the parasite. All progenies (seven F2 families) of 4 susceptible males were susceptible to experimental infection and their plasma did not lyse the parasite. It was presumed that these susceptible progenies were homozygous recessive (rr), and that the resistant allele was dominant. All progenies (two F2 families) of 1 resistant male (presumed RR) and 2 susceptible females were all resistant to infection and their plasma lysed the parasite. The ratio of resistant to susceptible charr in 6 other F2 families from the other 3 resistant males (presumed Rr) and two susceptible females was about 1:1. The results suggest a single Mendelian locus which determines innate resistance toC. salmositicainfection in brook charr and that it is possible to breedCryptobia-resistant fish.
The effect of two types of diet on populations ofAscaris suumandOesophagostomum dentatumin experimentally infected pigs
Authors: Petkevicius S. , Bjørn H. , Roepstorff A. , Nansen P. , Knudsen K. E. Bach , Barnes E. H. , Jensen K. 
Published: June 2009

SUMMARYThis investigation compared the effect of two common types of diet on worm burdens and faecal egg counts of pigs inoculated withAscaris suumandOesophagostomum dentatum. The diets were both considered nutritionally sufficient for pigs of this age, and gave high and comparable growth rates. Pigs were inoculated with both worm species at 14 weeks of age and slaughtered 3 or 12 weeks later. At 3 weeks,A. suumlarvae were numerous in the small intestine of pigs fed ground barley plus protein supplement, but were not detected from pigs fed a commercial full-constituent pelleted feed. At 12 weeks, however, average adult worm burdens were low and similar in both groups. At both slaughter times,O. dentatumworm burdens were significantly higher in pigs fed barley plus protein than in pigs given commercial feed, particularly for female worms, and the commercial diet led to worms being located further along the large intestine, and to reduced worm fecundity. The chemical composition of large intestinal contents differed significantly between pigs fed the two diets.
An analysis of the molluscan hosts of the trematodes of birds and mammals and some speculations on host-specificity
Authors: Ewers W. H. 
Published: June 2009

Data on 279 species of trematodes of birds and mammals are analysed in tables, to show the molluscan orders and families that act as first intermediate hosts of various trematode families.Host-specificity is highly developed in the first larvae of trematodes and it is suggested that, as a consequence of this, certain species, genera and families of molluscs harbour a greater variety of trematodes than others. The families Lymnaeidae, Physidae, Planorbidae, Hydrobiidae and Thiaridae are by far the most important first-intermediate hosts of the trematodes of birds and mammals whose life cycles are known; each family acting as host of not less than twenty-four species and eight families of trematodes.This paper is published with the approval of the Director General of Health, Canberra, A.C.T.
Schistosoma mansoni: in vivoandin vitrostudies of immunity using the guinea-pig model
Authors: Pearce E. J. , McLaren Diane J. 
Published: June 2009

SummaryIn vivoandin vitroparameters of immunity have been assessed in guinea-pigs sensitized with 500 normal or 500 radiation-attenuated cercariae ofSchistosoma mansoni. High levels of resistance to a challenge infection developed in both the chronic and irradiated vaccine model, but immunity was expressed earlier (week 4) and reached higher levels (90%) in the latter case. Vaccinated guinea-pigs have thus been shown to achieve greater resistance than the more commonly used rodent hosts.In vitrocytotoxicity assays have demonstrated that antibodies capable of participating in complement-dependent (lethal antibody) or eosinophil-mediated schistosomular killing, develop in the serum of guinea-pigs immunized with either normal or irradiated cercariae. The time course of development of the eosinophil adherence promoting antibody approximated in both models, the development of immunityin vivo, but the lethal antibody response paralleled the immune status of the animal only in the irradiated vaccine model
The water relations of the larva of Xenopsylla cheopis (Siphonaptera)
Authors: Sharif M. 
Published: June 2009

A considerable loss of water in the flea larva, through its defaecation and excretion as the result of the absence of rectal glands, through a profuse evaporation from the surface cuticle on account of its being a soil inhabitant, and from its tracheal system owing to the absence of an efficient closing apparatus of the spiracles, is compensated by the absorption of water with the food and through the cuticle, and by the utilization of metabolic water.It has been proved, by conducting experiments on the food composed of dried horse blood and yeast, with different degrees of moisture contents, and by controlling the quantity of the desiccated food and the duration of its exposure to a low effective humidity of 60% at 22° C., that the chief source of the gain of water in the larva of Xenopsylla cheopis is through the food.The closing mechanism of the spiracles of the flea larva plays only a small part in the control of evaporation at medial temperatures but not at extreme ones.There are intrinsic differences in the water requirements of the flea larvae of the two sexes, being slightly less in the male larva than in the female larva.I am greatly obliged to Lt.-Col. Sir Sahib Singh Sokhey, Director, Haffkine Institute, Bombay, for affording me facilities for the pursuit of these investigations. Mr T. N. Raste has helped me in the calculation of the data statistically, for which I am grateful to him.
The effect of physical agents on hydatid scolex viability
Authors: Fastier L. B. 
Published: June 2009

By employing a combination of sub-stage heating and supra-vital staining with eosin or neutral red it was found that viable and non-viable hydatid scolices could be distinguished microscopically. Using this technique a study of the effect of heat in vitro on hydatid scolices has shown that death resulted from exposures at 50° C. for 70 min. and at 55° C. for 30 min.Experiments on the effect of boiling in destroying the contents of fertile cysts embedded in sheep liver showed that when offal was added directly to boiling water destruction of scolices was complete after 40 min. boiling. When the infected liver was placed in cold water brought to the boil, scolex death was assured only after 30 min. subsequent boiling.Ultra-violet radiations of 2537 A. did not kill scolices under the conditions adopted. Although this wave-length would apparently be ineffective as a scolicicidal agent in surgery of the human hydatid cyst, irradiation of hydatid fluid containing scolices might offer a simple method for initial sterilization of scolex culture media.The author wishes to acknowledge many helpful suggestions and loan of the Hanovia lamp by Dr G. M. Richardson of the Virus and Immunology Research Department, Otago Medical School.
A study of the vector-parasite relationships in Schistosoma mansoni
Authors: Files Virginia S. 
Published: June 2009

In this study Australorbis glabratus from Puerto Rico, the Dominican Republic, Venezuela, Surinam and Brazil, Biomphalaria pfeifferi from Liberia, and B. boissyi from Egypt were exposed to strains of Schistosoma mansoni from Puerto Rico, Venezuela, Surinam and Egypt, and to seven cross-strains of S. mansoni. In many instances, incompatibilities between vectors and parasites of different endemic areas were noted. It is suggested that these incompatibilities might be accounted for in two ways: (1) interspecific and intraspecific differences between vectors in respect to the physiological factors that are responsible for the development of the parasite in the snail, and (2) physiological differences between strains of the parasite. Evidence would seem to show that there are interspecific physiological differences between Australorbis glabratus and Biomphalaria boissyi; and that there are intraspecific differences between Australorbis glabratus from Brazil and A. glabratus from other countries here dealt with. In addition, it would appear that the parasite of Egypt differs physiologically from the parasites of Puerto Rico, Venezuela and Surinam; and that the parasite of Brazil differs physiologically from the parasites of the latter countries.We wish to express our gratitude to the following persons for their co-operation in collecting and shipping snails for this study: Drs M. Abdel Azim, C. H. Barlow, J. O. Coutinho, A. Gabaldon, the late W. A. Hoffman, G. W. Luttermoser, J. Oliver-Gonzalez, H. A. Poindexter, Bichat de Almeida Rodriques and A. E. Wolff. We are also indebted to the late Dr W. A. Hoffman, Dr M. Mayer and Dr J. Alves Meira for sending us animals infected with Schistosoma mansoni.
Remarks on theilerioses and Theileria
Authors: Dschunkowsky E. 
Published: June 2009

1. Areas in which theileriasis occurs are characterized by conditions in which the native cattle do not show clinical manifestations of the disease, but introduced cattle suffer from an epizootic manifesting itself seasonally with varied intensity.2. The degree of virulence exhibited and the species of tick acting as vectors have only an indirect significance as an indication of species of the parasite.3. The facts relating to the development of Theileria in the tissues of infected animals and relation of this to developmental stages in the circulating blood are still far from clear.4. The development cycle of Theileria in the red cells of the circulating blood of sick animals is described, and proof given that this is characterized by the formation of anaplasmatic forms developing into ring-shaped forms in T. annulata and T. dispar, and probably in all forms except, possibly, T. parva.5. It is very desirable from the point of view of world economy that a special commission to study theileriasis in the different areas in which it occurs should be established on an international basis.
The ecology of immature phases of trichostrongyle nematodes: IV. Larval populations on lowland pastures
Authors: Crofton H. D. 
Published: June 2009

1. Permanent and temporary pastures were examined using a modification of Taylor's method.2. The goodness of fit of Neyman's Contagious Distribution Type A when applied to larvae on pastures is discussed.3. Examination of permanent pastures over a period of 3 years showed that the difference in time of maximum infestation was greater between fields in the same year than between years for the same field.4. Counts made on pastures where disease had occurred showed reasonably close agreement with Taylor's estimate.5. No larvae were detected on fields after ploughing and reseeding.6. The number of larvae per lb. of herbage on reseeded pastures was low, but the growth of grass masked the fact that the total population was relatively high at the end of the season.
The action of 2:4-diamino-6:7-diisopropylpteridine on normal, proguanil- and sulphadiazine-resistant strains ofPlasmodium gallinaceum
Authors: McConnachie Elspeth W. 
Published: June 2009

1. 2:4-diamino-6:7-diisopropylpteridine has an antimalarial index of 1:40, when tested againstPlasmodium gallinaceum.2. 2:4-diamino-1′-methylindolo-(2′:3′-6:7)-pteridine showed no activity againstP. gallinaceumin doses tolerated by the chick.3. Proguanil- and sulphadiazine-proguanil-resistant strains ofP. gallinaceumwere cross-resistant to 2:4-diamino-6:7-diphenylpteridine.4. Proguanil- and sulphadiazine-proguanil-resistant strains ofP. gallinaceumshowed no cross-resistance to 2:4-diamino-6:7-diisopropylpteridine, but were slightly hypersensitive to this compound.I wish to thank Dr A. Bishop for her interest in this work, and for advice and criticism. The work has been financed by the Medical Research Council.
Art and Moralism
Authors: Taylor Craig 
Published: June 2009

AbstractMrs. Digby told me that when she lived in London with her sister, Mrs. Brooke, they were every now and then honoured by the visits of Dr. Johnson. He called on them one day soon after the publication of his immortal dictionary. The two ladies paid him due compliments on the occasion. Amongst other topics of praise they very much commended the omission of all naughty words. ‘What! my dears! then you have been looking for them?’ said the moralist. The ladies, confused at being thus caught, dropped the subject of the dictionary. (H.D. Best, Personal and Literary Memorials, London, 1829, printed in Johnsonian Miscellanies Vol. 2, G. Birkbeck Hill (ed.) (London: Constable & Co.,1897))
Plato on Conversation and Experience
Authors: Robertson David 
Published: June 2009

AbstractPlato's dialogues show discourse strategies beyond purely intellectual methods of persuasion. The usual assumption is that linguistic understanding depends on a match of inner experiences. This is partly explained by an underlying engagement with the historical Gorgias on discourse and psychology, as well as Parmenides on philosophicallogos. In theGorgiasand theSymposium, speakers cannot understand alien experiences by philosophical conversation alone. There is no developed alternative model of understanding in the Platonic dialogues. The difficulties in bringing ‘philistine souls’ into Socratic alignment are the result of possessing an inferior soul, suffering misdirected passions, or missing the philosophy bug.
Characterization of a new thermostable direct haemolysin produced by a Kanagawa-phenomenon-negative clinical isolate of Vibrio parahaemolyticus
Authors: Honda* Takeshi , Abad-Lapuebla Marimin A. , Ni Yuxin , Yamamoto Koichiro , Miwatani Toshio 
Published: June 2009

SummaryThe production of two haemolysins, thermostable direct haemolysin (Vp-TDH) and a Vp-TDH-related haemolysin (Vp-TRH), by clinical isolates ofVibrio parahaemolyticushas previously been reported. Here we describe a third type of haemolysin (named Vp-TDH/I), which is produced by a clinical isolate (strain TH012) that is Kanagawa phenomenon negative. Vp-TDH/I was purified by a series of column chromatographies on DEAE-Sephadex A25, hydroxyapatite, Sepharose 4B and Mono Q. By physicochemical, biological and immunological analyses, Vp-TDH/I was demonstrated to be similar, but not identical, to Vp-TDH and Vp-TRH. The gene encoding Vp-TDH/I was cloned and the deduced amino acid sequence of Vp-TDH/I confirmed that Vp-TDH/I has a sequence different from those of previously known Vp-TDH and Vp-TRH. Not only purified Vp-TDH/I but also live cells of the Vp-TDH/I-producing strain induced fluid accumulation in ligated rabbit intestine. We conclude that this clinical isolate produces a new type of Vp-TDH-related haemolysin, which may be involved in the pathogenesis of this organism.
Evidence for a developmentally regulated prespore-specific glutamine synthetase in the cellular slime mould Dictyostelium discoideum
Authors: Dunbar Andrew J. , Wheldrake John F. 
Published: June 2009

SUMMARY
The enzyme glutamine synthetase (GS) is described for the first time in Dictyostelium discoideum. The appearance of this enzyme is developmentally regulated. The level of activity is low in vegetative cells and increases more than threefold during differentiation. Furthermore this enzyme is shown to be differentially localized in prespore cells, the specific activity being approximately fourfold higher than in prestalk cells. The enzyme has a pH optimum of 7.8 and 8.2 in the γ-glutamyltransferase and γ-glutamylsynthetase assays, respectively, and a temperature optimum of 45°C. Kinetic studies of GS revealed apparent Km values of 5.9 mM, 0.009 mM and 8.6 mM for glutamine, ADP and NH2OH, respectively, in the γ-glutamyltransferase assay, and of 2.2 mM, 0.12 mM and 0.64 mM for glutamate, ATP and NH2OH, respectively, in the γ-glutamylsynthetase assay.
Performance of three minimally invasive cardiac output monitoring systems
Authors: De Wilde R. B. P. , Geerts B. F. , Cui J. , Van Den Berg P. C. M. , Jansen J. R. C. 
Published: June 2009

SummaryWe evaluated cardiac output (CO) using three new methods – the auto‐calibrated FloTrac–Vigileo (COed), the non‐calibrated Modelflow (COmf ) pulse contour method and the ultra‐sound HemoSonic system (COhs) – with thermodilution (COtd) as the reference. In 13 postoperative cardiac surgical patients, 104 paired CO values were assessed before, during and after four interventions: (i) an increase of tidal volume by 50%; (ii) a 10 cm H2O increase in positive end‐expiratory pressure; (iii) passive leg raising and (iv) head up position. With the pooled data the difference (bias (2SD)) between COed and COtd, COmf and COtd and COhs and COtd was 0.33 (0.90), 0.30 (0.69) and −0.41 (1.11) l.min−1, respectively. Thus, Modelflow had the lowest mean squared error, suggesting that it had the best performance. COed significantly overestimates changes in cardiac output while COmf and COhs values are not significantly different from those of COtd. Directional changes in cardiac output by thermodilution were detected with a high score by all three methods.