bluuebunny/crossref_metadata_2025 huggingface dataset:
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.
Role of regulatory peptides in parasitic platyhelminths and their vertebrate hosts: possible novel factors in host-parasite interactions
Authors: Shaw C. , Johnston C. F.
Published: June 2009

The study of regulatory peptides has its origins in the classical work of Bayliss & Starling (1902). Their pioneering work on the presence of a factor in intestinal extracts which, when injected into the bloodstream of experimental animals, elicited pancreatic secretion, led to the genesis of the concept of the hormone, i.e. a chemical messenger which is released from one part of the body in response to a stimulus to travel in the bloodstream to a distant target tissue where it would elicit a physiological response appropriate to the original stimulus. In keeping with accepted scientific tradition, this concept had its critics. Pavlov, who had been studying secretory stimulation from a different perspective, concluded from his work on salivation in dogs, that this was mediated via neural pathways. With hindsight, and the benefits of knowledge obtained from nearly a century of scientific research, we now know that these pioneers were in actual fact studying different aspects of the same process and that both theories were complementary. In fact, it is becoming increasingly difficult to ascribe secretory control to either circulating or neuronal factors as both appear to be intimately involved in regulation.
Additions to the copepod parasites of South Indian fishes
Authors: Pillai N. Krishna
Published: June 2009

A collection of copepods from marine fishes, mainly elasmobranchs from South India was examined. Nine species are described of which six are new, one belonging to a new genus. The species described areCaligus dasyaticusRangnekar,C. lepeophtheropsissp.nov.Pseudopetalus dussumieri(Rangnekar),Dissonussp.,Nesippus vespaKirtisinghe,Kroyeria minutasp.nov.,Eudactylina lanciferasp. nov.,E. alatasp.nov., andEudactylinopsis curvatusgen.nov., sp.nov.
Inglisonema typos gen.nov., sp.nov., (Nematoda: Seuratoidea: Inglisonematinae, subfam. nov.) from an Australian bird
Authors: Mawson Patricia M.
Published: June 2009

Inglisonema typos, gen.nov., sp.nov., is described from Pitta versicolor Swainson, from Queensland. The new genus is distinguished by the presence of three teeth in a small buccal capsule, simple oesophagus, precloacal sucker with chitinous ring in the male, and unequal spicules. It is placed in the superfamily Seuratoidea; a new subfamily, Inglisonematinae, is proposed for it, differing from all others in the superfamily in the presence of unequal spicules.
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

The 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

Three 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

Establishment, 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.
The development of Haemonchus contortus in vitro: II. The effect of disulphide-reducing and sulphydryl-blocking reagents on the rate of development to the fourth-stage larvae
Authors: Mapes C. J.
Published: June 2009

Cysteine (20–100 mM) and reduced glutathione (20–80 mM) potentiated the development of the exsheathed third-stage larva of Haemonchus contortus to the fourth stage. The potentiating effect of cysteine was greatest during the short period before and after the exsheathment of the third-stage larva. Two hundred mM cysteine and 1 mM p–chloro-benzoate inhibited development. This inhibition was reversible. Ten mM iodoacetate and 0·5 and 5 mM n–ethyl-maleimide inhibited development of the larvae. The larvae appeared to be most susceptible to the inhibiting effects of these reagents during the period of development approaching the third moult. Development was either little affected or potentiated, when larvae were incubated with these reagents for short periods immediately after exsheathment.
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

Three 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

Some 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

Taenia 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

Neonatal 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

The 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

An 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

The 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.
Immunity to coccidiosis: protective effects of transferred serum and cells investigated in chick embryos infected withEimeria tenella
Authors: Elaine Rose M. , Long P. L.
Published: June 2009

The chick embryo proved to be an eminently suitable medium for immunological studies onE. tenellainfection, some of the difficulties encountered in the normal host, the hatched chicken, being circumvented.

Adoptive transfer of immunity toE. tenellainfections in the chick embryo was obtained with antibodies and with cells from caecal tonsils. Protective factors (antibodies) were demonstrated in the serum of fowls which had been infected withE. tenellaand in their progeny. Suspensions of caecal tosnil cells inoculated on to the CAM of developing chick embryos reduced the extent of subsequent infections withE. tenellaand this was particularly marked when the cell donors had been immunized withE. tenella.

Serum globulin protected only when the donors were becoming immune, i.e. after the third inoculum ofE. tenellaoocysts. The experiment was not continued to the point at which the serum donors were ‘solidly immune’, when previous attempts to protect passively with serum have failed.

Maternally transmitted protection was demonstrated in embryos only at the time at which peak protection was afforded by serum globulin, but this is probably an unsatisfactory method of testing since antibodies are not present in allantoic fluid until late in incubation, when coccidial infections are already well established.Some reduction in the oocyst output of the progeny of immunized hens was found when these were challenged at 4 days of age.

The protection given by the inoculation of suspensions of cells from the caecal tonsils may have resulted from the production of antibodies by these cells or from their interaction with the parasite in some form of cell-mediated immune mechanism.

We are grateful to Mrs Patricia Hesketh, Mr Martin Shirley and Mr Ron Waters for technical assistance and to Mr Peter Townsend for care of the animals.
Taenia crassicepssurface immunoglobulins: parasite- or host-derived?
Authors: McManus D. P. , Lamsam S.
Published: June 2009

In common with other taeniid cestodes, host or host-like proteins, especially immunoglobulins, occur on the surface and in the cyst fluid ofTaenia crassiceps metacestodes. Here, several approaches have been used to determine the origin of the immunoglobulins present on the tegument. Indirect IFAT showed that IgG was almost totally lost from the surface of bladders after 6 days culturein vitro. There was a rapid reacquisition of immunoglobulins following incubation of the cultured metacestodes with either normal mouse serum or mouse anti-T. crassicepsantiserum. Immunoprecipitation ofin vitrotranslation products and biosynthetically labelledT. crassicepsproteins with a panel of anti-IgG antisera failed to positively identify any molecule with homology to mammalian immunoglobulins. These results suggest strongly that the immunoglobulins located on the surface ofT. crassicepsare of host rather than parasite origin. The occurrence of a relatively low abundance receptor in the surface of the bladders, which binds non-specific host immunoglobulin, together with surface-bound specific anti-T. crassicepsantibodies can account for the presence of these host proteins. Freshly obtained bladders and metacestodes cultured in vitro for 6 days were transplanted into naive mice and the survival and development of the resulting parasites compared. In some individual mice there was a decrease in the number and volume of metacestodes and an increase in encapsulated parasites arising from cultured bladders. This was probably not related to the loss of host immunoglobulins from the parasite surface during culture as the reacquisition of these proteins after transplantation is likely to be far more rapid than any immune response could evoke in a naive host.
The relationship between the frequency distribution of Ascaris lumbricoides and the prevalence and intensity of infection in human communities
Authors: Guyatt H. L. , Bundy D. A. P. , Medley G. F. , Grenfell B. T.
Published: June 2009

Observed field data from a range of geographically distinct human communities suggest a consistent non-linear relationship between prevalence and mean intensity of Ascaris lumbricoides infection. Utilizing the negative binomial distribution as a description of observed aggregation, maximum-likelihood analysis reveals that the degree of aggregation is a negative linear function of mean worm burden. The factors responsible for this relationship in human populations require further study but may involve some combination of (i) density-dependent reduction in worm numbers within individuals, (ii) density-dependent parasite-induced host mortality or (iii) self-treatment by heavily infected hosts. Variability in the degree of aggregation appears dependent on the level of infection in a community and independent of geographical differences in the host or parasite populations.
Paracrystalline bundles of large tubules, induced in vitro by Mebendazole in Cysticercus cellulosae
Authors: Laclette J. P. , Merchant Marie Therese , Willms Kaethe , Cañedo L.
Published: June 2009

The effect of the anthelmintic Mebendazole on Cysticercus cellulosae maintained in culture medium was studied by transmission electron microscopy. In addition to the well-known morphological changes induced by Mebendazole in other cestode and nematode larvae, it also induced the cytoplasmic appearance of paracrystalline bundles in the secretory cells of the bladder wall. These bundles were formed by groups of large parallel tubules arranged in a hexagonal-like pattern. The tubules, which had an external diameter of about 50 nm and a length that might exceed 5 μm, were surrounded by a matrix and a distance between neighbouring tubules of 80–120 nm centre to centre was estimated. The tubules were stable to colchicine and low temperature. The temporary appearance of bundles is described and some alternative explanations on their origin are advanced.
Genetic and immunological characterization of the microsporidianSeptata intestinalisCali, Kotler and Orenstein, 1993: reclassification toEncephalitozoon intestinalis
Authors: Hartskeerl R. A. , Van Gool T. , Schuitema A. R. J. , Didier E. S. , Terpstra W. J.
Published: June 2009

Th relationships between theEncephalitozoon-likeSeptata intestinalisand other microsporidia that occur in humans, notablyEncephalitozoon cuniculiandEncephalitozoon hellem, is insufficiently documented using morphological descriptions alone. To assess mutual relationships, we have examined other phenotypic as well as genetic aspects ofS. intestinalis, obtained both from tissue culture and clinical specimens, in comparison with a number of other microsporidia. Phenotypic characterization was performed by analysis of the protein composition and antigenic structure of various microsporidian spores by SDS-PAGE and Western blotting. The genetic characterization consisted of the determination of the sequence of theS. intestinalis rrsgene encoding the small subunit ribosomal RNA (srRNA), restriction fragment length polymorphism (RFLP) analysis of amplifiedrrsgenes and establishment of the degree of sequence identity betweenrrsgenes of various microsporidian species. The unique sequence ofrrsofS. intestinalisas well as the distinct RFLP and SDS-PAGE profiles indicate thatS. intestinalisis clearly different from other human microsporidian species. However, itsrrsgene shared about 90% sequence identity withrrsof bothEncephalitozoonspp.,E. cuniculiandE. hellem. This is remarkably higher than the about 70% identity observed betweenrrsof microsporidian species which belong to different genera and thus suggests that S.intestinalisshould be regarded as a species of the genusEncephalitozoon. Western blots revealed a marked cross-reactivity betweenS. intestinalisand both species ofEncephalitozoonwhich also stresses the close relationship between these organisms. It is concluded thatS. intestinalisis so closely related toE. cuniculi, the type species ofEncephalitozoon, that it should be reclassified asEncephalitozoon intestinalis.
Chemical guidance of Onchocerca lienalis microfilariae to the thorax of Simulium vittatum
Authors: Lehmann T. , Cupp S. M. , Cupp W. E.
Published: June 2009

The behavioural responses of Onchocerca lienalis microfilariae (mf) to tissue factors of the surrogate black fly host, Simulium vittatum, were studied using a novel in vitro bioassay. Mf accumulated towards thoracic tissues to a density 4 times higher than towards abdominal tissues, despite the larger surface area and volume of abdominal tissues. Mf migrated toward thoracic tissues regardless of whether or not contact with thoracic tissues was possible. Therefore, mf directed themselves toward the thorax rather than arresting their movement after they make contact with thoracic tissues. Chemical cue(s) provided a principal guidance for mf to locate thoracic tissues. Mf lost their ability to differentiate thoracic and abdominal tissues following addition of thoracic attractant(s) to excised abdomens and reversed their differential response when excised thoraces were depleted of chemical cue(s). Mf did not respond to salivary gland product, but to other thoracic factor(s). Intact thorax that was connected to 1–2 abdominal segments attracted considerably less mf than excised thorax. However, intact thorax attracted more mf than excised abdomen. Abdominal tissue size did not affect thorax attractiveness. Involvement of a large molecular weight protein(s) was suggested by the high attractiveness of the 100 kDa Centricon concentrator retentate and complete precipitation of attractant(s) by ethanol.
The influence of the actionmycete,Pasteuria penetrans, on the host–parasite relationship of the plant-parasitic nematode,Meloidogyne javanica
Authors: Bird A. F.
Published: June 2009

The actinomycete,Pasteuria penetrans, is a specific endoparasite of various plant-parasitic nematodes. When parasitizing the root-knot nematode (Meloidogyne javanical) the nematode's capacity to reproduce is destroyed and feeding on and stimulation of the plant host are unaffected even though the bulbous body of the female nematode becomes filled with spores. Parasitism by the actinomycete does not alter the rate of growth in the early stages of nematode development although the non-parasitized female grows more rapidly than the parasitized one for a short time immediately after the final moult.Pasteuriadid not invade or inactivate the anterior oesophageal region of the femaleMeloidogyneor influence the morphology of the giant cells induced by these nematodes in their hosts' roots. The influence of this parasite on the developmental physiology of its nematode host is discussed.
The relation between the number of parasites/host and host age: population dynamic causes and maximum likelihood estimation
Authors: Pacala S. W. , Dobson A. P.
Published: June 2009

We examined dynamical factors that shape the distribution of the number of parasites/host in constant or temporally varying environments, and with or without host-age dependent variation in host susceptibility and parasite mortality. We predict properties of the parasite distribution in the absence of density-dependent factors such as densitydependent mortality or recruitment and parasite-induced host mortality. These properties provide a criterion for the detection of density dependence in temporally variable systems with host-age dependent interactions. We have then introduced methods to estimate and statistically evaluate the effects of host age or size on the distribution of parasites/host. The methods are based on a maximum likelihood protocol for linear and non-linear regression when data are negatively binomially distributed. We have illustrated the use of the theoretical results and statistical methods by re-analysing the data of Halvorsen & Andersen (1984) on cestode infections in Norwegian arctic charr and by analysing new data on nematode infections in Caribbean Anolis lizards.
Studies on the behaviour of Lucilia illustris Meigen as a parasite of vertebrates under experimental conditions
Authors: Dasgupta B. , roy Pranabesh
Published: June 2009

When egg-masses of Lucilia illustris, taken from carcasses, were mounted on the body of living vertebrates (Clarius batrachus, Bufo melanostictus, Rana tigrina, Hemidactylus fluviviridis, Columba livia and Suncus murinus), the larvae hatched in the majority of cases under normal conditions of room temperature, and entered into the body of the experimental hosts, ultimately killing them. It appeared that the larvae fed on the brain first before turning their attention to other soft tissues of the hosts. The specimens fed on living tissue had a shorter period of development than those bred on dead animals and the period of development was shortest when the host was a living warm-blooded animal.

Thanks are due to Mr H. Oldroyd of the British Museum of Natural History, London, for kindly identifying the fly. The authors also wish to thank Dr T. N. Ghosh of the Calcutta School of Tropical Medicine, who helped with literature; and Dr S. K. Das Gupta, of the Darjeeling Government College, who helped with suggestions at the time of preparing the manuscript.
Sequences in the maturation of the genitalia inTetrabothrius erostris(Loennberg, 1889) from the intestine ofLarus argentatus argentatusPontoppidan
Authors: Rawson Dilys
Published: June 2009

1. A detailed description, with illustrations, is given, of the sequences in development and maturation of the genitalia inTetrabothrius erostris.This is the first such account of any member of the new order Tetrabothridea.

2. The effect of the very marked protandry on the form of the remainder of the genitalia is discussed.

3. Attention is drawn to the unusual ovary which produces sclerotin and which it is proposed to call a ‘calycal-ovarium’.

4. Comparison is made of the embryophore with that of the Cyclophyllidea. There is a suggestion that the embryophore may be formed of sclerotin inT. erostris.

5. Par-uterine vesicles have been described for the first time in any member of the Tetrabothridea. These vesicles arise from the uterine primordium and have previously been confused with testes.

6. The complex affinities of the order Tetrabothridea are discussed and some support arises for the creation of this new order.
The susceptibility of fishes to haemoflagellates at different ambient temperatures
Authors: Woo P. T. K. , Wehnert S. D. , Rodgers D.
Published: June 2009

Trout acclimated to 20 °C could not be infected withCryptobia salmositica. Those acclimated to 5 °C had longer pre-patent periods and considerably lower parasitaemias than those at 10 °C. Forty days after infection, the parasitaemias in fish at 10 °C fluctuated, while this was not observed in those at 5 °C. In vitro incubation ofCryptobiain plasma from 20 °C fish did not affect the motility nor the infectivity of the parasite. Fish infected at 15 °C (low parasitaemias and 2 weeks after inoculation) lost their infections when the ambient temperature was raised to 20 °C. However, in fish with more acute infections (4 weeks after inoculation), the parasitaemias were only substantially reduced when the ambient temperature was raised to 20 °C.Trypanosoma danilewskyiwere detected in goldfish acclimated to 10, 20 and 30 °C. However, the parasitaemias in goldfish at 10 and 30 °C were consistently much lower than those at 20 °C.
Parasite development and adaptive specialization
Authors: Bianco A. E. , Maizels R. M.
Published: June 2009

The complex life-cycles of parasitic animals are a product of exploiting the process of development to generate organisms with different biological potentials within a species. Successive stages of the parasite adapt to functions such as host invasion and transmission, and to the colonization of a variety of niches, often involving different hosts, tissues or cells. Understanding the molecular basis of adaptive biology among parasities is a major challenge that lies at the heart of research in contemporary parasitology. Differences in scale at the levels of genomic complexity and cell biology exist between most parasitic protozoa and helminths, rendering a cautionary note to making generalized observations. The two principal approaches used to gain insights into adaptive specializations are to start with a biological activity and identify the molecule, or select molecules with particular properties and deduce function. Both have their part to play, with their inherent advantages and limitations, and both are illustrated with examples of studies on adaptive biology among parasitic nematodes.
On the egg of the tick, Ixodes ricinus L.
Authors: Arthur D. R.
Published: June 2009

The egg of Ixodes ricinus L. is described, and the increase in size during development is noted. It is suggested that the increase is due to the absorption of water. The egg wall consists of exo- and endochorion with a thin vitelline membrane, which becomes thicker as development proceeds and assumes a laminated appearance. The secretion layer of Gené's organ is described, and appears to function as a cement for holding the eggs together in the cluster. Chemical tests show it to be of a waxy nature.

It is deduced from experimental evidence that the egg shell is not absolutely rigid, and the weight of evidence favours the view that the shape of the egg shell is maintained by the internal pressure of the egg contents, and the elasticity of the shell.

The development processes as seen in the living egg are described. Hatching from the egg shell is brought about by a muscular force acting on a limited area at the posterior pole of the egg.

The writer is indebted to Mr Robert David, of Longlands Farm, Pyle, Dr A. D. Lees, of the Agricultural Research Council, and Mr Simeon, of the Glamorgan War Agricultural Executive Committee, for supplies of material; to Mr T. W. Tyssul Jones, M.Sc., for his assistance in checking the measurements of the egg dimensions, and to Mr L. Cowley, M.Sc., Assistant Curator (Department of Zoology), National Museum of Wales, and Dr P. Tate, Molteno Institute of Parasitology, Cambridge, for reading the original script and for making many useful suggestions and modifications.
The ecology of the sheep tick,Ixodes ricinusL. Host relationships of the tick: Part 1. Review of previous work in Britain
Authors: Milne A.
Published: June 2009

On the whole published data on the host relationships ofIxodes ricinusL. in Britain are rather inadequate, but the following points emerge:

The tick (stages unspecified) has been found on twenty-three mammal, twenty-one bird and one reptile species. These include both wild and domestic animals. There are no records of non-hosts. The host list is incomplete. Its length and variety suggest, however, that the tick will feed on practically any mammal or bird it may meet.

Tick stages found on fifteen mammal, twenty-one bird and one reptile species have been recorded. For a number of reasons (see text) ‘recorded’ absence of any tick stage from an animal is not necessarily reliable. This, together with the incompleteness of the host list, detracts a little from the assertion of several authors, namely, that in general larvae and nymphs occur on both mammals and birds, but adult ticks on mammals only.

No precise host-potentials for any wild species relative to sheep (or other important farm stock) have been published in Britain. But, in one area, Scottish mountain hare, red deer and roe deer have been slaughtered on a large scale because of their alleged importance as hosts. Very inadequate data from two authors seem to suggest that as normally stocked populations (a) grouse are negligible compared with sheep as hosts to female ticks, and (b) mountain hare and red deer may play quite an important part in maintaining female ticks. Suggestion (b) at least should not be taken seriously until comprehensively investigated.

One author shows that an ‘appreciable’ tick population was maintained on a hill grazing by a reduced wild fauna in the absence of sheep.

Another author shows that the tick population of a grazing was considerably reduced by acaricidal treatment of sheep, together with almost complete extermination of a section of the wild fauna. Unfortunately, the two factors cannot be disentangled.

We would like to thank Mr Charles Elton, Director, Bureau of Animal Population, Oxford, and Dr J. MacLeod of the Cooper Technical Bureau, Berkhamsted, for criticism of the MS.; Mr F. Wallace for information on red deer stocking; and Dr V. B. Wigglesworth, F.R.S.,. Director, Agricultural Research Council Unit of Insect Physiology, Cambridge, within whose organization the work was done.