bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Wellcome Trust Lecture
Authors: Mitchell G. F. 
Published: June 2009

AbstractThe modern biology era in which molecular analyses dominate and immunology, cell biology and molecular genetics are prominent, has created unprecedented opportunities for the vaccine developer. The need for new and improved vaccines against many infectious disease agents is also great, no more so than for the protozoan and helminth parasite scourges of the rural poor in the tropical, less-industrially developed world. Despite the opportunities and needs, no vaccine against any human parasite yet exists nor does any molecular vaccine against any parasite; this chapter is a general discussion on the reasons for this state of affairs that assuredly will change soon.
Chairman's concluding remarks
Authors: Ogilvie Bridget M. 
Published: June 2009

SummaryThis meeting included talks which covered both the principles and problems of vaccine development and others that extensively reviewed the present state of progress towards the goal of antigenically defined parasite vaccines for human and veterinary use. Several speakers, particularly Drs Morrison and Gutteridge, pointed out that in comparison with bacteria and viruses there are few vaccines available against parasites and these consist of attenuated organisms for veterinary infections. Therefore, despite the intensity of effort, better defined vaccines for parasites still elude us.
A study on adaptation tolerance: growth of ascaridoid larvae in indigenous and non-indigenous hosts
Authors: Sprent J. F. A. , McKeown Ann 
Published: June 2009

A marked difference in the rate and extent of growth of the third-stage larvae of Amplicaecum robertsi was observed in the liver of indigenous Australian rats, as compared with non-indigenous rats. This difference was not correlated with the number of larvae recovered. The suggestion is made that the greater growth in indigenous rodents might be due to the availability or accessibility of a growth factor in the former group, or a manifestation of ‘adaptation tolerance’, an immunological unresponsiveness arising from adaptation in a geographically isolated host-parasite association. Observations on incidence of natural infection supported the hypothesis in relation to Rattus assimilis but not to Melomys cervinipes.Thanks are due to Dr C. Dobson for help with the presentation of results.
A report on the occurrence of microvillus-like structures in the caeca of certain trematodes (Paramphistomatidae)
Authors: Wotton R. M. , Sogandares-Bernal F. 
Published: June 2009

The observations presented in this study indicate that the filose projections emerging from the apical or luminal surface of the epithelial cells lining the caeca of the trematodesCleptodiscus kyphosiandC. reticulatusare sterocilia or microvilli. Their activity in the animal appears to be concerned with the absorption of substances from the lumen of the blindly ending caeca rather than with movement of material.Acknowledgement is made that part of this work was carried out in the Department of Zoology and Anatomy of the University of Nebraska, Lincoln, Nebraska, and supported in part by a grant from the Nebraska Heart Association for 1959.
Observations on the use of Trichostrongylus colubriformis (Nematoda) infections of guinea-pigs for laboratory experiments
Authors: Sturrock R. F. 
Published: June 2009

Four groups of guinea-pigs were infected with a range of doses of T. colubriformis. The infections were followed by egg counts and weight measurements, and the adult worms were recovered from the animals post mortem. A multivariate analysis, details of which are given in an appendix, showed that the sensitivity of the measures used was, in descending order, final weight, total egg count and worm burden. The course of the infection is discussed in view of the apparent self-cure mechanism. Precautions are outlined for the experimental use of this hostparasite relationship.The author is grateful to Professor B. G. Peters for his advice on this work, to Dr P. Silverman of Allen and Hanburys Limited for a supply of T. colubriformis infective larvae and to Dr R. E. Blackith for his advice on the statistical treatment of the data.
The effect of cysteine and B group vitamins on the skin of the white laboratory mouse infested with the mite Myocoptes musculinus (Koch)
Authors: Watson Doreen P. 
Published: June 2009

1. Mice were given a supplement of nicotinic acid, riboflavin or B complex from 1 to 6 months.2. One mouse of each group was then infested with Myocoptes musculinus for a period of 1 week or 8 weeks. At infestation the supplement was discontinued. Alternatively infestation lasted 8 weeks, the supplement being continued until death.3. The mitotic rate was estimated for the epidermis of clean and infested mice and the rates compared.4. Other mice were fed cysteine for periods of three months, one was then infested for a period of 8 weeks before being killed and the mitotic rates of the clean and infested mice compared.5. It was found that after supplementing the feed of the mice by members of the B group vitamins, quite large numbers of mites (M. myocoptes) could be carried without deleterious effect to the host and without signs of mange.6. With cysteine supplementation, no gross signs of mange were seen but the mite affected the skin by raising the mitotic rate in the malpighian layer.I wish to thank Vitamins Limited for supplying the vitamin supplements; and the Royal Free Hospital School of Medicine for facilities for carrying out the work; also Dr A. M. Hughes for her helpful guidance at all stages of the work and especially for reading the paper.
The effect of dietary amino acids on the growth ofHymenolepis diminuta
Authors: Hopkins C. A. , Young R. A. L. 
Published: June 2009

The effect of an amino acid imbalance in the diet on the growth ofHymenolepis diminutain rats was reinvestigated. The claims of earlier workers that growth of the tapeworm is retarded was not substantiated.The size frequency distribution of 575, 13-day-oldH. diminutarecovered from 9- and 10-worm infections was determined, to reveal the shape of the distribution and total variance. The total variance in worm weights was analysed to determine the amount attributable to variance ‘between rats’ (comparison of the mean weight of the worms recovered from rats) and variance between worms within individual rats. ‘Between rats’ variance was found to account for > 80% of the total variance.Assuming variance equal to that in the experiments described, the degree to which experiments can determine a difference in effect between two diets on the growth of tapeworms is analysed, and the degree to which this is altered by increasing the number of rats in dietary groups and/or decreasing the ‘between rats’ variance is estimated.The suitability of various procedures for host dietary experiments on tapeworms is discussed; these include the duration of the experiment, feeding regime, age of worm and the relative advantages of weighing worms singly or in groups.We gratefully acknowledge the technical help we have received from Miss Patricia Grant and Mr Jack Keys. Our thanks are also due to Mr Robert Elton of the University of Glasgow Statistics Department who has advised us on statistical procedures and calculated Table 6.
Crescentovitus biloculus gen.nov., sp.nov., a fish cestode (Caryophyllaeidae) from Nagpur, India
Authors: Murhar B. M. 
Published: June 2009

A list of the genera of the family Caryophyllaeidae known from India is given. Crescentovitus biloculus gen.nov., sp.nov. from the coelom of the siluroid fish, Heteropneustis fossilis, is described and its systematic position discussed. An up-to-date key to the genera of the subfamily Lytocestinae is included.I desire to express my deep gratitude to Professor M. A. Moghe for his helpful criticism in the preparation of this paper, and to Mr N. A. Shastri, Principal M.M. College of Science, Nagpur, for the kind co-operation extended to me. My thanks are due to Mr S. C. Theophilus, Head of Botany Department, Hislop College, Nagpur for helping me in various ways.
The oncomiracidium of Capsala martinieri, a monogenean parasite of the sun fish (Mola mola)
Authors: Kearn G. C. 
Published: June 2009

The anatomy of the oncomiracidium of Capsala martinieri, a monogenean skin parasite of the sun fish Mola mola, is described and compared with that of the oncomiracidium of Entobdella soleae, a skin parasite of the common sole Solea solea.The oncomiracidium of C. martinieri is characterized by the occurrence of an extensive bilaterally symmetrical and constant pattern of body pigment of unknown function.
The relationship betweenTrichuris trichiuratransmission intensity and the age-profiles of parasite-specific antibody isotypes in two endemic communities
Authors: Needham C. S. , Bundy D. A. P. , Lillywhite J. E. , Didier J. M. , Simmons I. , Bianco A. E. 
Published: June 2009

SUMMARYThe present study compares parasite-specific antibody responses in two Caribbean communities with high and low levels ofTrichuris trichiuratransmission. The age-dependency of antibody levels suggest that IgG1and IgG2levels relate to the current intensity of infection (as assessed by density of eggs in stool (e.p.g.) and reflect the age–intensity profile at the population level. IgG4, IgE and IgA levels persist into early adulthood and the subsequent decline is gradual. In the low transmission area, lower infection levels are reflected in lower parasite-specific antibody levels (of all isotypes) in the community as a whole. Despite a significantly greater past experience of infection in the high transmission area, antibody levels are not maintained at significantly higher levels throughout adulthood. The production of IgA appears to require a threshold for triggering, and a vigorous IgA response is maintained into early adulthood only in the high transmission village where peak intensity is greatest and the age-convexity of intensity is most marked. Experimental and theoretical studies focusing on the dynamic nature of host–helminth interactions in hosts exposed to high and low infection levels, and the putative role of acquired immunity, are discussed in relation to the data presented.
Voltage-gated currents in muscle cells of Schistosoma mansoni
Authors: Day T. A. , Orr N. , Bennett J. L. , Pax A. 
Published: June 2009

SUMMARYThree morphologically distinct types of muscle fibres isolated from the platyhelminth Schistosoma mansoni have been studied with whole cell current- and voltage-clamp techniques. Fibres showed a marked time-dependent decrease in membrane resistance in response to depolarizing current injections. Voltage-clamp experiments revealed the presence of two distinct voltage-gated outward currents. The most prominent current is a slowly activating, slowly and incompletely inactivating potassium current similar to delayed rectifier currents which have been described in a variety of cell types from a variety of organisms. Also present is a faster activating, quickly and completely inactivating potassium current that shares functional characteristics with ‘A’-currents. All three of the cell types studied possess a delayed rectifier current, but only two of the three types have ‘A’-currents. Though depolarization with high K+ leads to contraction of the dispersed fibres, no voltage-gated inward currents could be detected by whole cell voltage-clamp under any of our conditions.
Establishment, survival, site selection and development ofLeptorhynchoides thecatusin largemouth bass,Micropterus salmoides
Authors: Leadabrand C. C. , Nickol B. B. 
Published: June 2009

SUMMARYEstablishment, survival and distribution ofLeptorhynchoides thecatus(Acanthocephala) were investigated in largemouth bass,Micropterus salmoides, fed 10, 25, or 40 cystacanths and examined at 1, 3 or 5 weeks post-infection. Worms established widely in the alimentary tracts of bass but by 5 weeks post-infection had localized in the pyloric caeca and intercaecal region. Other individuals moved to parenteral sites where they remained immature, though viable. In the 10- and 25-level exposures, establishment and survivorship in the alimentary tract were roughly proportional to the dose of cystacanths. After 1 week post-infection in the 40-level exposure class, numbers of worms in the alimentary tract decreased significantly and parenteral occurrence increased significantly. Total survival ofL. thecatusappeared to be density-independent. Maturation of worms was retarded temporarily as intensity of infection increased, but by 5 weeks post-infection worms from all doses were at roughly the same stage of development within sex. The caeca and intercaecal area apparently did not differ in their suitability for maturation.
Movement patterns and photosensitivity of Trichonema spp. infective larvae in non-directional light
Authors: Croll N. A. 
Published: June 2009

1. Trichonema spp. infective larvae once stimulated move in darkness, dim and bright visible light and ultra-violet light. There was no significant difference between the distances moved in these photic conditions.2. Movement patterns were variable but certain shapes of tracks, rates of reversal and reversing types were typical of certain light conditions.3. The rate of reversing was dependent on light conditions and was random in direction.4. Sensory adaptation was suggested in visible light, but not in ultra-violet at 366 μm.5. Movement analyses in flashing light suggested that pulsating stimuli at intervals of 100 ms or less were required for sensory input approximating to physiologically continuous stimulation.6. Larvae showed an idiosyncrasy in their tracks, repeated tracking with the same individual giving less varied tracks than with different larvae.The author is indebted to Mr J. M. Smith for his painstaking efforts in preparing the tracks and his willing and skilful assistance throughout.
Electrophysiology ofAscarismuscle and anti-nematodal drug action
Authors: Martin R. J. , Valkanov M. A. , Dale V. M. E. , Robertson A. P. , Murray I. 
Published: June 2009

SUMMARYThree groups of anthelmintic drugs act directly and selectively on muscle membrane receptors of parasitic nematodes. These groups of anthelmintics are: (1)The Nicotinic Agonists(levamisole, pyrantel, morantel and oxantel) that act on acetylcholine receptors of nematode somatic muscle; (2)The GAB A Agonist, piperazine, that acts on nematode muscle GABA receptors; and (3)The Avermectinsthat open glutamate gated Cl-channels on nematode pharyngeal muscle. The electrophysiology and pharmacology of muscle and neuromuscular transmission the nematode parasite,Ascaris suum, is outlined and effects of anthelmintics that interfere with transmission described. Resistance to anthelmintics has appeared in some parasitic nematodes but the mechanisms of this resistance remain to be determined
Some factors affecting the severity of infection withEimeria tenellain chicken embryos
Authors: Long P. L. 
Published: June 2009

SUMMARYSome factors affecting the suceptibility of chick embryos toE. tenellainfection have been examined. An incubation temperature of 41°C was found to be more suitable for the development of the parasite than 38 or 39°C. At the higher temperature development of schizonts was more rapid and mortality caused by the parasite occurred earlier and was substantially greater. Mortality, caused byE. tenella, was dose related and doses between 15000 and 45000 sporozoites produced 100 % mortality in embryos incubated at 41°C.There were differences in the susceptibility of three strains of W.L. embryos toE. tenellainfection; ‘S’ strain W.L. embryos were more susceptible than either ‘C’ or ‘K’ strains. However, the susceptibility was not evident in hatched chickens of the ‘S’ strain.Two laboratory strains ofE. tenella(‘W’, ‘H’) were shown to produce different mortality levels in embryos; the ‘W’ strain was markedly more virulent, perhaps because schizonts of the 2nd generation matured more rapidly in both embryos and chickens inoculated with this strain ofE. tenella.I wish to thank Dr R. K. Cole of Cornell University for making three strains of W.L. embryos available to me for this work. I also wish to thank the Governing Body of the Houghton Poultry Research Station; the Agricultural Research Council and the Avian Diseases Department of Cornell University for making it possible for me to undertake a substantial part of this work at that University in 1968. Grateful thanks are due to Dr P. P. Levine, D. L'Amoreaux and M. S. Shirley for their help at various stages of the work.
Protein antigens in the cyst fluid of Taenia saginata cysticerci
Authors: Joshua G. W. P. , Harrison L. J. S. , Sewell M. M. H. 
Published: June 2009

SUMMARYTaenia saginata cyst fluid proteins from 4, 8, 12 and 16-week-old cysticerci were analysed by a combination of direct I radio-isotope labelling, immunoprecipitation using a panel of sera from infected cattle infected with T. saginata and SDS–PAGE. Protein antigens of 12, 14, 16, 20 and 26 kDa were identified in all of the cyst fluids examined. These were immunogenic and were precipitated by serum taken from cattle from 8 weeks after infection onwards and were therefore considered to be of diagnostic potential. A 185 kDa protein antigen found only in the cyst fluid of 4-week-old cysticerci and a 43 kDa protein antigen first detected in cyst fluid from 8-week-old cysticerci were also identified but were considered to be of more limited diagnostic potential due to their restricted presence. An apparently non-immunogenic 67 kDa protein, found in all the cyst fluids examined, may have been host serum albumin.
Necator americanusin the DSN hamster: density-dependent expulsion of adult worms during primary infection
Authors: Rose R. A. , Behnke J. M. 
Published: June 2009

SUMMARYNeonatal hamsters were exposed to varying doses ofNecator americanuslarvae and changes in the stability of the resulting worm burdens were monitored over a period of 25 weeks. No change in worm burdens was evident for the first 5 weeks of infection, irrespective of the infection intensity, but the more heavily infected groups subsequently lost worms in a density-dependent manner. Male and female hamsters lost comparable proportions of their established parasite burdens indicating that there was no host sex-linked difference in this respect. By week 15 infections had stabilized and the residual worm burdens, usually a maximum of 30 worms survived for a considerably longer period of time. Initially the percentage of male worms varied from 45% to 50% but as infection progressed male worms comprised a significantly increasing proportion of the total worm burden. By week 25 the percentage of male worms was usually in excess of 60%. The growth of infected animals was not severely affected byN. americanus, even when heavy worm burdens established initially, but a significant effect was detected particularly in week 5, prior to worm loss, when the adult worms would have been feeding on intestinal tissues and causing blood loss for a period of about 2 weeks. The most severe depression in the packed cell volume was also recorded in week 5, indicating that anaemia had been initiated in infected hamsters. Whilst, the regulation of parasite burdens in weeks 5–10 post-infection may have resulted from host immunity, the persistence of the residual worm burdens, the marked density-dependent anaemia and the subtle effect on host weight, all reflected well-documented aspects of chronic human necatoriasis.
The effect of transmission-blocking antibody ingested in primary and secondary bloodfeeds, upon the development ofPlasmodium bergheiin the mosquito vector
Authors: Ranawaka G. , Alejo-Blanco R. , Sinden R. E. 
Published: June 2009

SummaryThe effects of purified monoclonal immunoglobulins from control, or transmission-blocking anti-Pbs21 antibodies, upon the infection ofAnopheles stephensiby ookinetes ofPlasmodium bergheiare compared. Anti-Phs21 antibody reduced mean intensity and prevalence of infection by 94·7 and 58·7% respectively if added to the infectious bloodfeed at a concentration of 100 μg/ml. Fab fragments were of similar efficacy. No transmission enhancement was detected with declining antibody concentrations. Addition to subsequent (second) feeds reduced mean oocyst intensity but not prevalence. The reduction in blockade declined from 41% at day 2, to 4% at day 8. Second bloodfeeds, containing control globulin taken 4 or 6 days (but not 2 days) after infection, increased sporozoite burden in the salivary glands. At all times anti-Pbs21 reduced sporozoite number in the thorax compared to time-matched controls, but again highest gland intensities were obtained when the second bloodfeed was given on day 4. We conclude that second bloodfeeds containing transmission-blocking antibody simultaneously serve two opposing roles, (1) inhibition of parasite development and (2) the supply of nutrients which permit more sporozoites to be produced by each oocyst.
In vitro feeding of instars of the ixodid tick Amblyomma variegatum on skin membranes and its application to the transmission of Theileria mutans and Cowdria ruminantium
Authors: Voigt W. P. , Young A. S. , Mwaura S. N. , Nyaga S. G. , Njihia G. M. , Mwakima F. N. , Morzaria S. P. 
Published: June 2009

SummaryAn in vitro feeding method using rabbit or cattle skin membranes, applied successfully to all stages (larvae, nymphae and adults) of the ixodid tick, Amblyomma variegatum, is described. The feeding apparatus consisted of a blood container with a membrane placed on top of a tick containment unit. A carbon dioxide atmosphere of between 5 and 10% and a temperature of 37 °C were used as stimulants for the attachment of the ticks. High CO2 concentrations in the atmosphere improved the feeding success of all instars. The effect of anticoagulation methods for the bloodmeal was investigated, and heparinized blood was found to be the most suitable for tick feeding. When the bloodmeal was replaced by tissue culture medium for feeding nymphs the subsequent moulting success was reduced. Adult ticks of both sexes remained attached for up to 16 days, until completion of their bloodmeals. All stages of the tick fed on whole blood in the artificial feeding system and all reached engorged weights less than those achieved by control ticks fed on experimental animals. A large proportion of ticks, fed artificially on whole blood, moulted or laid eggs successfully. The method was successfully applied for the transmission of Theileria mutans and Cowdria ruminantium to cattle.
Protein synthesis and release by cultured schistosomula ofSchistosoma mansoni
Authors: Harrop R. , Wilson R. A. 
Published: June 2009

SummaryThe lung schistosomulum ofSchistosoma mansoniis the target of protective immunity in mice singly vaccinated with irradiated cercariae. Since the effector responses are T cell-mediated, their initiation requires the release of antigens from the intact parasite. We have used the technique of biosynthetic labelling with ‘35S’methionine, before and after transformation of the cercariae, to analyse the kinetics of protein synthesis and release by the schistosomulum. In addition, the proteins present in the soluble fraction of the parasite and those released duringin vitroculture have been characterized. During a 7-day culture period schistosomula derived from labelled cercariae lost proteins most rapidly within the first 3 h after transformation. Two proteins of molecular weight 61 and 20 kDa were dominant and may correspond to areas of proteolytic activity. Analysis of the rate of protein synthesis of schistosomula labelled after transformation revealed four different phases, which may relate to the developmental processes occurringin vivo. During the first 24 h, synthesis was very low, increasing to a plateau and then rising to a peak at day 8; thereafter the rate declined rapidly. Whilst some stage-specific synthesis of proteins was detected in the soluble fractions of the parasite bodies, the pattern of proteins released by cultured larvae was remarkably uniform. At least 15 proteins were detected by autoradiography with bands at 61, 45 and 20 kDa being particularly prominent. These proteins merit further study as potential mediators of the protective immune response.