bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of a low protein diet and a glucose and filter paper diet on the course of infection ofNippostrongylus brasiliensis
Authors: Clarke Karen R.
Published: June 2009

Rats were fed on two deficient diets and were infected withN. brasiliensislarvae. They were autopsied at times ranging from 18 hours to 17 days after infection. The effect of the diets on worm burden, sex ratio of the worms and size of larvae and of worms were noted. Significantly more larvae reached the lungs and intestine in rats fed on glucose and filter paper (G.F.P.) and low protein (L.P.) diets than in controls, the highest numbers coming from G.F.P. rats. Neither the migration rate nor the development of the worms was accelerated by the deficient diets. G.F.P. and control rats lost larvae soon after their arrival in the intestine. Adult worms were lost from rats on the deficient diets before they were lost in significant numbers by controls; this was not due to the initially larger worm burdens in the former rats. G.F.P. and control rats lost the bulk of their infections by 17 days; L.P. rats retained about 50% of the worm burden they had on the fourth day. The effect of the deficient diets on the migratory and adult phase ofN. brasiliensis, and on susceptibility and resistance is discussed.

This work was done during the tenure of a Science Research Council Studentship. My thanks are due to Dr E. T. B. Francis for his helpful and critical supervision, and to Professor I. Chester Jones, in whose Department the work was carried out, for the facilities he provided.
Macrolecithus papilliger sp.nov. (Digenea: Allocreadiidae, Stossich, 1904) from Phoxinus phoxinus (L.). Morphology, histochemistry and egg capsule formation
Authors: Rees Gwendolen
Published: June 2009

Macrolecithus papilliger sp.nov. from the stomach and intestine of Phoxinus phoxinus (L.) is described and its systematic position discussed. The life span in the fish, in captivity during January, is 5–6 weeks. The sequence of events in release of oocytes from the ovary and egg capsule formation has been observed in living specimens. Mature oocytes, in the ovary, are enclosed in groups of eight in a transparent membrane which ruptures, releasing them singly into the ovicapt. The egg capsule is formed in two stages: a transparent membrane is secreted, probably by Mehlis's gland, around the oocyte and vitelline cells in the ootype; later this is reinforced by vitelline globules released from the vitelline cells. These coalesce on the inner side of the membrane. The operculum is formed in the ootype. Histochemical tests support the observations.

I would like to express my gratitude to Mr S. Prudhoe, British Museum (Nat. Hist.), for helpful comments on this species and to Mr M. C. Bibby and Mrs M. Fisher for technical assistance.

The work was supported by a grant from the Science Research Council, for which I am most grateful.
Studies on the host–parasite interface of strigeoid trematodes
Authors: Erasmus David A.
Published: June 2009

The adhesive organ of Apatemon gracilis minor Yamaguti, 1933, consists of two lobes lying in a cup-shaped fore-body. The cytoplasmic tegument covering the apposing faces of the lobes is different from that covering their outer surfaces. The covering of the outer surface corresponds to the general tegument present on the rest of the body, whereas that on the inner surfaces is finely pitted and in certain regions is elevated to form a coarse reticulum. This specialized surface is covered externally by a plasma membrane and is in continuity with nucleated cell bodies lying below the basement layer. The cell bodies contain large quantities of granular endoplasmic reticulum as well as several Golgi complexes and numerous mitochondria. Masses of secretion bodies are present and these also occur in the extensions to the external tegument as well as within the external tegument of the lobes. When the parasite is attached the inner faces of the lobes come into contact with the vascular lamina propria of the host. The possible biological role of this specialized host–parasite interface is discussed and it is suggested that this surface specialization may form a morphological basis for the ‘placental’ function suggested for the adhesive organ by earlier workers.

The author wishes to acknowledge the research grant provided by the S.R.C. for the purchase of a vacuum coating unit and an AEI EM 6 electron microscope. The progress of this study was greatly facilitated by the excellent assistance of Mr T. Davies and Miss C. Green. The Stereoscan micrographs are published by permission of the Cambridge Instrument Company.
The in vitro action of immune pig serum on second - and third-stage Ascaris suum larvae
Authors: Taffs L. F.
Published: June 2009

Third and artificially hatched second-stage larvae of A. suum were exposed to the action of saline and normal and homologous immune pig serum. Precipitates developed at the mouth, excretory pore, anus and around the cuticle of third-stage larvae when they were placed in immune pig serum, but not in saline or normal serum. Precipitate was most evident at the excretory pore and was often the first precipitate to form. It is suggested that the excretory products may play an important role in stimulating the production of antibody in the host. A relationship was noted between the antibody titre of the serum and the amount of precipitate, the life span of the larvae, their activity, and the rate at which precipitates formed. It is concluded that the titre of the serum was in some degree a measure of the ability of the host to resist reinfection.

Circumlarval precipitates did not form when second-stage larvae were placed in samples of the same immune serum. It is pointed out that this may be due to the lack of sufficient antigenic material available to react with antibody in the antisera. It is also suggested that an absence of sufficient larval antigen may also partly account for the small degree of resistance exhibited by the resistant host within the first 2 or 3 days of reinfection.

The work, which is abstracted from a Ph.D. thesis, was carried out in 1957 under the tenure of an Animal Health Trust Wellcome Fellowship. I am grateful to Dr Soulsby, under whose guidance this work was carried out.
Physiological studies on trematodes—Fasciola giganticacarbohydrate metabolism
Authors: Goil Madan M.
Published: June 2009

1. Studies have been made of carbohydrate metabolism inFasciola giganticaduring starvation and these are compared with data available about carbohydrate metabolism inF. hepatica.

2. InF. giganticathe glycogen content before starvation was 5·4% of f.w. or 25·35% of D.W. of tissue, and the glycogen content after starvation was 3·5% of F.W. or 16·29% of D.W. of tissue.

3. The medium in whichF. giganticawas incubated was analysed for lactic acid as one of the end products of glycogen consumption. The lactic acid given out in a period of 2 hr. was 0·46% of F.W. or 2·18% of D.W. of tissue.

I wish to thank Professor K. Sahai for his generous help in the preparation of this manuscript.
Studies on the egg of the horse bot-fly,Gasterophilus intestinalis(De Geer)
Authors: Tatchell R. J.
Published: June 2009

1. A description is given of the egg ofGasterophilus intestinalis.

2. The chorion has been shown to consist of a number of tanned protein and lipoprotein layers.

3. The waterproofing of the egg is shown to be dependent on a primary wax layer on the inner membrane of the endochorion and a secondary layer on the vitelline membrane.

4. The respiratory requirements of the egg are supplied from a free-air space between the inner membrane and the tanned protein layer of the endochorion which communicates with the atmosphere by specialized pore canals opening into the follicular grooves.

Thanks are due to Dr P. Tate for suggesting the subject of this work and for his advice and encouragement during its progress.
A study of resistance to cycloguanil inPlasmodium gallinaceumin chicks
Authors: Bishop Ann
Published: June 2009

A cycloguanil-resistant strain ofPlasmodium gallinaceumwas produced relatively rapidly by passage through chicks treated with low but effective doses of the drug, the dose being increased as resistance developed.

The strain was cross-resistant to proguanil but not to pyrimethamine or chloroquine.

A strain highly resistant to proguanil was resistant to cycloguanil but only slightly resistant to pyrimethamine.

A strain highly resistant to pyrimethamine was resistant to proguanil and cycloguanil.

Passage for 20 months through birds treated with doses of cycloguanil which suppressed infection for relatively long periods failed to change the sensitivity of the strain to this drug or to proguanil. Although the relatively large dose did not eradicate the infection in any of the birds, subinoculations demonstrated that parasites were absent from the blood for a period in some of the birds, though infections finally developed.

I am indebted to Parke Davis and Company for the supply of cycloguanil, to Imperial Chemical Industries Ltd. for the proguanil hydrochloride and chloroquine phosphate and to Burroughs Wellcome and Company for the pyrimethamine base.
Studies on the structure and histochemistry of the male reproductive tract of Aspiculuris tetraptera (Nematoda: Oxyuridea)
Authors: Anya A. O.
Published: June 2009

The histological anatomy of the male reproductive tract as well as the cytochemistry of the cells of different regions of the male tract in Aspiculuris tetraptera are described.

It is shown that there are at least three different regions of the vas deferens, each of which releases one or more substances into the lumen of the male system and thus contributes to the composition of the semen. The histochemical nature of these secretions is given and it is suggested that the secretions of the distal vas deferens are oxytocic.

My thanks are due to Professor J. D. Smyth of the Australian National University, Canberra, for the gift of RNA-ase (L. Light and Co.) and some other histochemical reagents, to Dr T. R. R. Mann, C.B.E., F.R.S., and Dr D. L. Lee, for helpful discussions during the course of this study and for reading the draft manuscript.
The transmission of Theileria parva (Theiler, 1904) by Rhipicephalus carnivoralis Walker, 1965
Authors: Brocklesby D. W. , Bailey K. P. , Vidler Brenda O.
Published: June 2009

R. carnivoralis has been shown to be capable of transmitting T. parva under experimental conditions and stages of the protozoon have been found in sections of salivary glands of the tick.
Malaria parasites of some Brazilian lizards
Authors: Walliker D.
Published: June 2009

From lizards caught in the Codajaz region, Amazonas, Brazil, the following malaria parasites are described:

Plasmodium rhadinurum Thompson & Huff, 1944 from Iguana iguana L.

A species of Plasmodium from Ameiva ameiva L.

A species of Plasmodium from Cnemidophorus lemniscatus (Daudin).

I wish to express my thanks to the Instituto Nacional de Pesquisas da Amazonia (I.N.P.A.) at Manaus for their help in the collection of material; to Professor P. C. C. Garnham, C.M.G., F.R.S., for assistance in identification, and to Mr P. E. Nesbitt for advice on staining procedures. This work was carried out during the tenure of a Medical Research Council Scholarship for Training in Research Methods.
On some interesting nematode parasites of fish from Pakistan
Authors: Rasheed Suraiya
Published: June 2009

Two interesting and unusual Spiruroid parasites have been reported from the intestines of marine fish. These are referred to the new genera and species, namely, Bulbocephalus inglisi and Cestocephalus serratus. The former is characterized by a globular head and the muscular oesophagus has two bulbs in its most anterior part. The glandular portion of this oesophagus is 20–25 times as long as the muscular part. The diganosis of Cestocephalus serratus is mainly based on the presence of an oblong head which is covered anteriorly by lobe-like structures in the manner of bothridia in some Cestodes. A new subfamily (family Spiruridae) has been proposed to accommodate Bulbocephalus gen.nov. The family or subfamily diagnosis of Cestocephalus gen.nov. has been restricted at present due to the paucity of material.

The writer wishes to express her gratitude to Professor J. J. C. Buckley for his interest throughout this work.
A new malaria parasite in Hylopetes alboniger Hodgson
Authors: Dasgupta B. , Pal Nandalal , Chatterjee Amal , Chatterjee Dipak
Published: June 2009

Tissue stage and erythrocytic stages of a new malaria parasite Rayella hylopetei n.sp., is described from a Particoloured flying squirrel Hylopetes alboniger Hodgson encountered in Darjeeling. Tissue stages are represented by schizonts in the form of cystic bodies occurring in characteristic foci of infection occurringi n the liver. Schizonts are absent in the erythrocytes, and it appears that all immature stages in the erythrocytes directly develop into gametocytes. Haemozoin pigments occur in the form of black granules. The infected red blood cells are slightly enlarged and are without stippling.

The investigation received financial support from the World Health Organization.
On the histology, histochemistry and ultrastructure of the cysticercoid of Raillietina cesticillus (Molin, 1858) Fuhrmann, 1920 (Cestoda, Cyclophyllidea)
Authors: Baron P. J.
Published: June 2009

The structure of the cysticercoid of Raillietina cesticillus has been studied with the aid of light and electron microscopes. While the ultrastructure of the superficial parts of the scolex closely resembles that of other cestodes, the fine structure of the cyst wall differs from both these. The arrangement and functions of the tissues in the cyst wall are discussed and interpreted with reference to the tissues of the scolex of the cysticercoid of R. cesticillus and to the tissues of other cestodes. R. cesticillus cysticercoids, subjected to various histochemical tests, were shown to contain proteins and carbohydrate materials.

The author wishes to thank the Principal and Governors of West Ham College of Technology, a constituent college of the North-east London Polytechnic, for their general and financial support of this work. Thanks are also due to the Directors and Governors of the several institutions whose electron microscopes the author used. The work described here forms part of a thesis approved by the University of London for the degree of Ph.D.
Parasitic mites of Surinam
Authors: Desch Clifford , Lebel Robert R. , Nutting W. B. , Lukoschus F.
Published: June 2009

Demodex carolliae, a parasite of the bat Carollia perspicillata, is described for all stages of its life cycle. The sequences and adaptive features of this life cycle are detailed. Some information is presented on the population structure and the pathogenicity of this species.

This research was supported in part by Grant W83–1 to Dr F. Lukoschus from the Netherlands Foundation for the Advancement of Tropical Research (WOTRO).
Investigations into the free-living phase of the life-cycle of Nematodirus helvetianus
Authors: Rose J. H.
Published: June 2009

The free-living phase of the life-cycle of Nematodirus helvetianus was studied out of doors on grass plots and the effects of temperature and humidity on the free-living stages were studied in the laboratory. The results of these observations are discussed in relation to the bionomics of N. battus and N. filicollis, and tentative deductions made regarding the epidemiology of N. helvetianus infection.

I wish to thank Mr J. Bailey for technical assistance.
Infections of the three-spined stickleback, Gasterosteus aculeatus L., with the plerocercoid larvae of Schistocephalus solidus (Müller, 1776), with special reference to pathological effects
Authors: Arme C. , Owen R. Wynne
Published: June 2009

Infections are described of Gasterosteus aculeatus in a pond at Leeds with the plerocercoid larvae of Schistocephalus solidus.

Very heavy infections were found in the summer of 1962 and early 1963; many fish harboured over 50 worms and the maximum was 130.

For each individual host the relative percentage parasite-weight to host-weight has been determined (parasitization index). In more than 50% of the fish the P.I. exceeded 25; the maximum value was 68·5. The relationship between P.I., numbers of worms and weight of worms is described.

Some effects of parasitization on the host are described; they include gross distension of the body, reduction of liver weight, reduction of packed cell volume of erythrocytes and delay in oocyte maturation. In some heavily parasitized individuals spawning is apparently inhibited.

Concurrent infections with the microsporidian Glugea anomala are described.

Our thanks are due to Mr A. Rennie, B.Sc., of the Yorkshire Ouse and Hull River Authority for drawing our attention to the source of infected sticklebacks, to Mr A. O. Holliday for the preparation of photographs and to Mr G. R. Standley for assistance in the preparation of the slide shown in PI. 1, fig. 3. We also wish to thank Dr J. N. Ball, Department of Zoology, University of Sheffield, for his helpful comments on the gonads of infected fish, and Professor J. M. Dodd, Department of Zoology, University of Leeds, for providing facilities and much helpful discussion. One of us (C. A.) gratefully acknowledges the receipt of a Science Research Council Research Studentship and Fellowship.
Immunity to Eimeria brunetti and Eimeria maxima infections in the fowl
Authors: Rose M. Elaine
Published: June 2009

Fowls were completely resistant to a third inoculation with E. maxima oocysts given after two graded and spaced infections. Resistance was complete to a fourth inoculation of E. brunetti oocysts after a series of three infections.

Birds made resistant to E. maxima and then inoculated with E. brunetti showed very little evidence of this infection when the intestines were examined on the sixth day and they passed very few oocysts in the faeces. The resistance of E. brunetti-immunized chickens to E. maxima infection was not quite so strong. The results indicate that, under the conditions of the experiment, infection with either of these species will protect in some degree against subsequent infection with the other. These results suggest that the species specificity of acquired resistance is not so complete as previously reported.

I am indebted to my colleague, Mr P. L. Long, for his interest throughout the experiment and, in particular, for assistance with the examination of the intestines. The excellent technical assistance of other members of the Parasitology Department is also gratefully acknowledged. Mr Paul Rogers took the photographs.
The ecology of the tick Ixodes trianguliceps Birula (Arachnida; Acarina; Ixodoidea)
Authors: Cotton M. J. , Watts C. H. S.
Published: June 2009

The ecology of the tick Ixodes trianguliceps Bir. is described from material collected at two localities in Wytham Estate near Oxford. The hosts examined were bank voles, Clethrionomys glareolus Schr., field voles, Microtus agrestis (L.), and field mice, Apodemus sylvaticus (L.).

The seasonal distribution of the tick is biannual, with spring and autumnal peaks as found in Ixodes ricinus (L.). Larvae occur throughout the year but principally in spring and autumn. Nymphs are found only from late spring until the autumn, and adults principally in the spring with a small peak in autumn.

Larvae and nymphs of I. trianguliceps were more abundant on male than on female bank voles, but there was no significant difference in the infestation of males and females by adult ticks. Similarly there was no significant difference in the infestation of adult and juvenile bank voles.

Larvae and nymphs occur principally on the ears, but the adult ticks are found mainly on the neck or body, although the ears were not excluded from infestation.

The seasonal distribution and life-history is discussed with reference to similar studies made in the Soviet Union and in Poland. Male ticks were found in copula on the host, and both males and nymphs were collected from the nests of voles.

A tentative summary of the life-history of I. trianguliceps is given based on known facts for the hedgehog tick, Ixodes hexagonus Leach, which has a similar seasonal occurrence.

We wish to thank Professor Don Arthur for identification of much of the tick material, especially in the early stages of this study, and for useful criticism of the draft manuscript. The work was carried out while one of us (M.J.C.) was a research student in the Hope Department of Entomology, Oxford, and the other (C.H.S.W.) a research student at the Bureau of Animal Population, Oxford. For facilities in both departments we wish to express our gratitude.
On cyclical alterations in the Feulgen staining of nuclei during the development of nematodes
Authors: Monné L.
Published: June 2009

In the Ascaroidea the germinal vesicle, the pronuclei and the nuclei of all the blastomeres prior to chromatin diminution are strongly Feulgen positive. The nuclei of the somatic cells, which become suddenly Feulgen negative upon chromatin diminution, gradually become strongly Feulgen positive again during subsequent development. The nuclei of the germ track cells which are not subjected to chromatin diminution remain strongly Feulgen positive during the whole development. In all the other metazoa, including the nematodes where chromatin diminution does not occur, the germinal vesicle, the synkaryon and the nuclei of the blastomeres during the earliest cleavage stages are Feulgen negative. The latter, however, become gradually strongly Feulgen positive again during the subsequent development. The nuclei of the female germ cells and the synkaryon of protozoa and plants have also been reported to be Feulgen negative. Thus, the Feulgen-positive nuclei of the definitive somatic cells always originate from Feulgen-negative nuclei, in the Ascaroidea from the Feulgen-negative nuclei of the blastomeres and in all other forms of life from the Feulgen-negative nuclei of the eggs. The Feulgen-positive nuclei of the germ cells also originate from Feulgen-negative nuclei except in the Ascaroidea, where they originate from Feulgen-positive nuclei. In the somatic track the sequence of Feulgen-positive nuclei is interrupted in all forms of life and during the germ track it is also interrupted in all forms of life except the Ascaroidea, where it is uninterrupted. These biologically important phenomena are discussed.

These investigations have been supported by a grant from the Knut and Alice Wallenberg stiftelse. The author is indebted to Mrs. M. Wahlström and E. Nowak for their valuable technical assistance.
The hatching mechanism of the egg of Fasciola hepatica L.
Authors: Wilson R. A.
Published: June 2009

The hatching mechanism of the liver fluke egg was investigated and a new interpretation put forward. Light stimulates the miracidium and, when fully activated, the miracidium is responsible for altering the permeability of the membrane on the internal concave surface of the viscous cushion. Prior to expansion the cushion (a fibrillar mucoprotein complex) is in a dehydrated or semihydrated state. The change in permeability of the enclosing membrane allows the fluid egg contents to permeate into the cushion. The fibrillar matrix becomes hydrated and an increase in volume occurs. This compresses the miracidium and sacs and an internal pressure is set up which gradually increases until the operculum finally ruptures and flies back violently. The cushion and miracidium are then expelled by the hypertonicity of the egg contents.

I would like to thank Professor O. W. Richards, in whose department this work was carried out, also Dr F. Call and Professor B. G. Peters for their many helpful criticisms. I am also grateful to Miss Mary Morris for assistance with the electron microscopy.
The histopathology of Fasciola hepatica infections in sheep
Authors: Dow C. , Ross J. G. , Todd J. R.
Published: June 2009

Experimental infections of lambs with Fasciola hepatica are described. The growth rate of the parasite, time of entry to the bile ducts, and time of patency are recorded and a preferential migration of the parasite in the liver parenchyma noted. The gross and histological lesions produced in the liver from 1 to 40 weeks after infection are described and compared with previous observations in cattle.

The parenchymal migration of the parasite is shown to consist of two phases, a free migrating phase up to the 6th week, and a localized phase after the 6th week prior to entry into the bile ducts. Hepatic cell regeneration is observed and hepatic fibrosis is minimal. The localized phase of migration is associated with a unique peripheral palisade of giant cells in the fluke tracts and with the formation of pseudofollicular aggregation of lymphocytes. The presence of flukes in the bile ducts produces fibrosis of the duct walls. The walls, however, remain pliable and expanded to accommodate the parasites and calcification was never observed.
Vitamin requirements of the Coccidia of the chicken
Authors: Warren E. W.
Published: June 2009

For normal development of the parasites, Eimeria acervulina and E. tenella in the chicken, dietary thiamine, riboflavin, biotin, nicotinic acid and folic acid are required. E. acervulina required thiamine for second schizogony and sporulation; riboflavin for first schizogony and possibly gametogony, biotin for the development of the sporozoites/trophozoites and for gametogony, and nicotinic acid for schizogony and gametogony. E. tenella required thiamine and riboflavin for gametogony; biotin for first schizogony; and nicotinic acid for second schizogony.
Immunization against cerebral pathology inPlasmodium berghei-infected mice
Authors: Curfs J. H. A. J. , Hermsen C. C. , Meuwissen J. H. E. TH. , ELING W. M. C.
Published: June 2009

The development of cerebral lesions inPlasmodium berghei-infected mice was dependent on the Strain of mice and the size of the infectious inoculum. In particular, C57B1/6J mice develop cerebral lesions when infected with low numbers of parasitized erythrocytes. By increasing the number of parasites in the infectious inoculum, the percentage of animals that develop cerebral malaria is decreased. Varying degrees of protection against the development of cerebral malaria can be obtained by several methods of immunization. (1) Injection of mice with large numbers of disrupted parasitized erythrocytes 1 or 2 weeks before the challenge infection (protection up to 70%). (2) A 2-day immunizing infection given 9 or 14 days before the challenge infection (protection up to 85%). (3) Injection of mice with plasmodial exoantigen preparations 1 week before the challenge infection (variable protection-rate, up to 100%). In all mice protected against cerebral malaria, parasitaemia is not affected by the immunizing treatment, indicating that protective mechanisms against cerebral malaria and parasitaemia are independent.
Genetic influences upon eosinophilia and resistance in mice infected withTrichinella spiralis
Authors: Lammas D. A. , Wakelin D. , Mitchell L. A. , Tuohy M. , Else K. J. , Grencis R. K.
Published: June 2009

Genetic influences upon host variation in eosinophilia and resistance to helminth infection, and the relationship between these parameters, were investigated in 7 inbred and 1 hybrid strains of mice infected withTrichinella spiralis. Clear strain-dependent variations were observed in the maximum peripheral blood, bone marrow and spleen eosinophilia attained in infected animals. SWR, NIH and SJL strains of mice all gave high responses to infection; four congenic strains sharing the B10 background (C57BL10 [B10], B10.S, B10.G and B10.BR) were low responders. Some of the genes for high responsiveness appeared to be dominant, as F1 hybrids from high- and low-response phenotype parental strains showed intermediate to high responses to infection. Intestinal eosinophilia showed no correlation with either peripheral blood or bone marrow responses (NIH and B10 strains having similar levels of eosinophil response in gut tissue) and was unrelated to the level of resistance to infection. Whereas NIH were highly resistant, with adult worm burdens at 13 days post-infection and muscle larval burdens at 35 days post-infection significantly lower than all other strains, B10 were quite susceptible, retaining substantial worm burdens at day 13 and harbouring large numbers of muscle larvae. Measurements of the level of the eosinophilopoietic cytokine IL-5 in sera during infection showed that the two strains differed in the kinetics of release but not in their absolute capacity to produce this cytokine. NIH mice released high levels during a primary infection, B10 released high levels during a secondary infection. The relationship between eosinophilia and resistance and the differences seen between responses in different body compartments are discussed in terms of genetically determined influences operating at the levels of T helper cell populations, T cell cytokines and bone-marrow precursor cell populations.
The effects of age, temperature, light quantity and wavelength on the swimming behaviour of the cercariae of Cryptocotyle lingua (Digenea: Heterophyidae)
Authors: Rea J. G. , Irwin S. W. B.
Published: June 2009

Laboratory experiments indicated that the active life-span of the cercariae of Cryptocotyle lingua was temperature-dependent. An increase in water temperature and population age both correlated with a tendency for the organisms to become decaudate. The larvae were strongly photoresponsive to lateral light but with time, horizontal swimming rates (HSRs) from release point to light source progressively declined. When measured over a range of light quantities, HSRs peaked at 30 μM/m2/s. HSRs were also influenced by water temperature. A rapid increase occurred up to 15 °C after which there was a precipitous decline. HSRs to coloured light were negatively correlated with increasing wavelength. When offered a choice between colours, cercariae favoured the shorter wavelengths. The implications of these responses for successful transmission are discussed.
On the transmission, biology and morphology of Echinococcus granulosus equinus, a new subspecies of hydatid tapeworm in horses in Great Britain
Authors: Williams R. J. , Sweatman G. K.
Published: June 2009

1. A 12·8% incidence of hydatid infections occurred in 709 horses examined in England. By contrast, hydatid cysts do not occur in horses in New Zealand where Echinococcus granulosus granulosus is common in sheep, cattle and swine.

2. Experimentally, scolices from hydatid cysts from English horses reached a gravid state in laboratory dogs. It was not possible to infect horses with E. g. granulosus of sheep-dog origin, and only one of two sheep became infected with two cysts following the ingestion of eggs of English horse-dog origin.

3. Our observations, together with those of others on secondary hydatid cyst formation, indicate that the two types are not only biologically but morphologically distinct.

4. In the horse-dog worms, the cirrus sac tilts anteriorly at an acute angle; the testes (about 35) are distributed throughout the proglottid with two or three rows posterior to the vitelline gland, and persist in proglottids when some mature eggs are present; the average length of the rostellar hooks is greater than in E. g. granulosus.

5. It is proposed that the horse-dog material be named E. g. equinus subsp. nov.

6. Rostellar hooks from cysts in British cattle resembled morphologically those from horses, while those from a British sheep and from man were like the hooks from hydatid cysts in man and livestock in New Zealand.

7. A red deer, hedgehog and European rabbit were not infected artificially following the ingestion of eggs of E. g. equinus.

Mr J. T. Briggs, Chief Public Health Inspector, Public Health Department, Bently, Doncaster, England, was responsible for the inspection of the British horses reported in this paper. We are indebted to Mr Briggs for this courtesy and for sending us fresh hydatid cysts from horses for experimental purposes. Mr N. Aitken was responsible for maintaining the experimental horses in an area of New Zealand known to be free of E. granulosus. Our thanks are also due to Messrs G. D. Page, D. V. Weston, Miss L. A. Duncan and Mrs B. R. Clarke for their able technical assistance.
Effect of temperature on the development of free-living adults of Strongyloides papillosus (Wedl, 1856)
Authors: Premvati
Published: June 2009

Strongyloides papillosus is found to be very common in the Lucknow area where 90% of the sheep are infected. The life-cycle is predominantly indirect, or heterogonic. The development of mature free-living adults takes place between 20° and 37° C., and 34° C. is the optimum temperature. At a temperature of 25° C., the percentage of free-living adults is 60–65 in summer (March to November) and practically 100 in winter (December to February). Immature females can develop at 40° C. in summer, but not in winter, under laboratory conditions.

Inhibition experiments in a hot oven incubator with varying percentages of humidity, and in a humidity chamber incubator with constant 100% humidity, maintained at temperatures varying from 40° to 50° C., show that in the humidity chamber incubator mature free-living adults develop at 34° C. after incubation for 12 hr. at 40° C., after 4 hr. at 42° C., after 2 hr. at 45° C. and after 15 min. at 50° C. The hot oven incubator allows mature free-living adults to develop at 34° C. after 8 hr. at 40° C., after 2 hr. at 42° C., after 1 hr. at 45° C. and after 15 min. at 50° C.
The infestation of the redfishSebastes marinus(L.) andS. mentellaTravin (Scleroparei: Scorpaenidae) by the copepodsPeniculus clavatus(Müller),Sphyrion lumpi(Krøyer) andChondracanthopsis nodosus(Müller) in the eastern North Atlantic
Authors: Williams I. C.
Published: June 2009

1. An account is given of the intensity and incidence of infestation of the scorpaenid redfish,Sebastes marinusandS. mentella, by the parasitic copepodsPeniculus clavatus, Sphyrion lumpiandChondracanthopsis nodosuson three fishing grounds in the eastern North Atlantic, namely Iceland, Bear Island and the Barents Sea.

2.Peniculus clavatuswas found to be a rare parasite on both species of redfish in the eastern North Atlantic. Adult female parasites were found during the months from September to February only; they were usually attached to the pelvic or dorsal fins of the host causing little damage.

3.Sphyrion lumpiwas found to be a comparatively rare parasite on the deep-waterSebastes mentellathroughout the eastern North Atlantic but it was found onS. marinusin the vicinity of Bear Island only. It seems justifiable to regard the Bear Island grounds as a centre of abundance ofSphyrion lumpiin the eastern North Atlantic. Adult femaleS. lumpitended to infest medium-sized redfish more often than smaller or larger fish.

4. The infestation ofSebastes marinusandS. mentellabyChondracanthopsis nodosushas been examined in some detail and attention directed to the influence on infestation of the host species, geographical distribution, body length, age and sex of the host, and seasonal variations. The distribution of femaleC. nodosuswithin the gill chamber of the two species of redfish is described; it appears to be related to the need of the parasite to secure a protected and spatially limited habitat out of the mainstream of the ventilation current through the gill chamber.

5. The ecological relationships betweenSebastes marinusandS. mentellaand the three species of parasitic copepod are described together with the possibility of using these and other parasites as indicators of the host's mode of life. It is concluded thatChondracanthopsis nodosusandSphyrion lumpimerit more detailed and extensive study as possible parasitological indicators of different stocks of redfish.

I wish to express my thanks to Messrs Jackson Mills Ltd., Fish Merchants and Curers, Hull, and to the Officer-in-Charge, D.S.I.R., Humber Laboratory, Hull, for their generous assistance in making redfish available for examination. I am also most grateful to Miss E. C. Howard, Librarian, Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, for her invaluable assistance in providing certain otherwise unobtainable references in the literature.
Effects of Eubothrium salvelini (Cestoda) on the behaviour of Cyclops vernalis (Copepoda) and its susceptibility to fish predators
Authors: Poulin R. , Curtis M. A. , Rau M. E.
Published: June 2009

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

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

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

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

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

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

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

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

This paper reviews naturally occurring and synthetic compounds that either enhance immune defences or lower both natural and acquired immunity. Immunomodulatory agents used both for laboratory study and clinically for the management of immunologically based diseases are considered