bluuebunny/crossref_metadata_2025 huggingface dataset:
Biochemical and histochemical studies on the non-specific phosphomonoesterases ofFasciola giganticaCobbold 1855
Authors: Probert Allan J. , Goil Madan , Sharma R. K.
Published: June 2009

Biochemical studies on the non-specific phosphomonoesterases ofFasciola hepaticahave shown the presence of acid phosphomonoesterase active at pH 4·6 and two forms of alkaline phosphomonoesterases active at pH 7·6 and pH 9·6 respectively. Histochemical studies have located acid phosphomonoesterase in the walls of the intestinal caeca and to a lesser extent in the tegument. Alkaline phosphomonoesterase was found to occur mainly in the excretory ducts and to a lesser degree in the uterine wall. Glycogen was mainly concentrated in the yolk glands, parenchyma, mature eggs and the non-muscular regions of both oral and ventral suckers.

Dr A. J. Probert takes pleasure in recording the support of the British Council and the Indian University Grants Commission to enable him to study in India.
The role of the spleen in relation to natural and acquired immunity to infections ofBabesia rodhainiin the rat
Authors: Phillips R. S.
Published: June 2009

In the system investigated the spleen was essential in most rats for the acquisition of immunity and its maintenance in the presence of the piroplasm.

It is stressed that model immunological systems involving the role of the spleen do not simulate the complexity of a parasitic infection. The roles of the spleen as an antibody producer, and as a site of phagocytosis and haemopoiesis are discussed in relation to the control ofBabesia rodhainiby the rat. The possibility that the piroplasm may be able to undergo antigenic variation is considered.
Changes in the chemical composition ofHymenolepis diminuta(Cestoda:Cyclophyllidea) during prepatent development within the rat intestine
Authors: Mettrick D. F. , Cannon Christine E.
Published: June 2009

The changes in the percentage chemical composition of both complete strobilae, and of the immature, mature, and gravid regions of the strobila ofHymenolepis diminutahave been studied during development of the worms from 5 to 16 days postinfection. The chemical components that have been evaluated are non-protein nitrogen, protein nitrogen, ribonucleic acid, deoxyribonucleic acid,lyo-glycogen,desmo-glycogen and total lipid.

While the nitrogen, RNA and DNA fractions, expressed asμg/mg of worm dry weight, all decreased markedly with increasing worm age and size, the carbohydrate and lipid fractions increased over the same period of development.

In worms up to 7 days old there is a high non-protein nitrogen value, high RNA and DNA fractions, thelyo-glycogen component of the total carbohydrate is very large, but the amount of carbohydrate expressed as a percentage of dry weight is low. These values are associated with the very high rate of metabolism of the young worms. From 7 to 16 days postinfection the rate of growth slows considerably, which is reflected in the corresponding decreases in the non-protein nitrogen, RNA and DNA fractions, and the increase in the total carbohydrate percentage.

The changes in the chemical composition along a complete strobila complement the morphological evidence as the emphasis switches from segmentation to tissue differentiation and organ maturation.

The changes with age in the percentage composition of the same region of the strobila show that neither the complete worms nor the different regions of a strobila are static in terms of their chemical components, but are changing systems which may be correlated with the ontogenetic development and migrational behaviour of the worms.
A field study of nematode parasite populations in the lactating ewe
Authors: O'Sullivan B. M. , Donald A. D.
Published: June 2009

A typical postparturient rise of parasite egg output occurred in a group of lactating ewes. At parturition these animals carried few inhibited fourth-stage larvae and the rise was associated with a net increase in parasite populations, which did not occur in non-lactating ewes. Lactating ewes whose established parasite populations were effectively removed just prior to parturition showed a similar rise derived entirely from infection acquired during lactation, which was of much greater magnitude than that seen in similarly treated non-lactating animals. Circumstantial evidence of increased fecundity of T. colubriformis females in lactating ewes was also obtained.

It was concluded that the postparturient rise of egg output may derive from an increase in adult parasite populations by an increased rate of establishment of newly ingested infective larvae which develop to the adult stage without inhibition, as well as by the resumption of development of previously inhibited fourth-stage larvae. In addition, both newly acquired and established adult female parasites may show increased fecundity.

Ewes whose lambs were removed at birth or after a period of lactation showed a rapid fall in faecal egg counts associated with rejection of part of their existing worm burden and a pronounced increase in resistance to new infection.

All of the differences observed between lactating and non-lactating ewes in the behaviour of their parasite populations were found to be qualitatively the same as those that have been frequently reported in susceptible and resistant non-reproductive sheep. The hypothesis is suggested, therefore, that the postparturient rise derives from a pronounced but temporary relaxation of immunological control of gastro-intestinal nematode infection associated with the endocrine status of the lactating ewe.
Changes in body weight and intestinal absorption during infections with Eimeria acervulina in the chicken
Authors: Preston-Mafham R. A. , Sykes A. H.
Published: June 2009

Heavy infections of E. acervulina result in a depression in body weight of the host, but anorexia induced by the disease is not the only factor responsible for this, since normal birds starved to the same extent did not lose as much weight. It was shown that the absorption of l-histidine and glucose from the infected part of the small intestine was depressed and may be a contributory factor to this weight loss; restricted feed intake alone tended to increase, rather than decrease, absorption.
Cultivation of infective forms ofTrypanosoma congolensefrom trypanosomes in the proboscis ofGlossina morsitans
Authors: Gray M. A. , Cunningham I. , Gardiner P. R. , Taylor A. M. , Luckins A. G.
Published: June 2009

Two stocks ofTrypanosoma congolensewere established in culture at 28 °C using trypanosomes from the proboscides of infectiveGlossina morsitans. Successful primary cultures were initiated by placing an infected tsetse proboscis beside a bovine dermal collagen explant in Eagle's minimum essential medium supplemented with foetal calf serum. The trypanosomes multiplied rapidly in the medium and also gradually formed an adherent layer on the plastic surface of the culture vessel. Three primary cultures produced organisms infective for mice from 14, 20 and 35 days after initiation and thereafter continuously until days 76, 76 and 52 when they were discarded. Four attempts to initiate infective cultures using infected tsetse proboscides in medium without dermal explants were unsuccessful. When trypanosomes from primary cultures were placed in culture medium with proboscides from uninfected tsetse flies, the parasites multiplied, formed an adherent layer in the culture flasks and were seen in the proboscides within 24 h. A line of 1 stock was serially sub-passaged in this way 4 times during a period of 215 days. Infectivity titrations in mice indicated that primary and sub-passaged cultures each contained similar numbers of infective organisms. Another line of the same stock was also sub-passaged 4 times in medium alone over a period of 186 days. These sub-cultures again retained infectivity for mice, but titrations showed a decrease in infective organism production in the 4th sub-culture. Primary and sub-passaged cultures all included a variety of morphologically different developmental forms ofT. congolense, closely resembling those described in the labrum and hypopharynx ofGlossinaby previous workers. Short metacyclic-like trypanosomes and organisms with proteinaceous surface coats were present in infective cultures. Cultures were successfully re-established after cryopreservation at −196 °C and retained the ability to produce infective organisms.
Ecological studies of larval ticks in South Africa (Acarina: Ixodidae)
Authors: Londt J. G. H. , Whitehead G. B.
Published: June 2009

The distribution of larval ticks in relation to vegetation cover was studied on two coastal farms in the Port Alfred district of the Cape Province. The following five species were found:Boophilus decoloratus(Koch),Amblyomma hebraeumKoch,Ixodes pilosusKoch,Haemaphysalis silaceaRobinson andRhipicephalus evertsiNeumann.B. decoloratuspredominated in short protected vegetation,I. pilosusandH. silaceain short covered vegetation andA. hebraeumin medium-to-tall protected vegetation.R. evertsiwas collected in too small numbers to allow any correlation to be established. BothI. pilosusandH. silaceademonstrated activity peaks during the winter months. Microclimatic measurements indicated that larval ticks were not usually collected in microhabitats which experienced midday saturation deficits in excess of approximately 10 mm Hg. Behavioural studies on larval ticks climbing glass rods demonstrated the possible association of larvae with a definite vegetation height. The optimal vegetation heights were correlated with field data. The water balance of some tick species was studied and it was found that at 26 °C a relative humidity of 70% or more (i.e. above 7·53 mm Hg saturation deficit) was required by these larvae. Larvae lost water to the atmosphere at humidities lower than this value and took up water vapour from the atmosphere at values higher than 70% R.H. They were shown to be able to imbibe water through the mouthparts, and this possibly has survival value.
The ultrastructure of the parasite—host interface of three tetraphyllidean tapeworms of the elasmobranchRaja naevus
Authors: McVicar A. H.
Published: June 2009

Ultrastructural examination of the parasite-host interface of three tetraphyllidean cestodes ofRaja naevus(sectioned attached to the intestine) indicates that while the strobilar tegument of each closely follows the typical cestode pattern that of the bothridia has several modifications probably associated with attachment. Microtriches similar to those of the strobilum are absent, although small spines onEcheneibothriumsp. andPhyllobothrium pirieiand wart-like structures onAcanthobothrium quadripartitumbothridia are considered to represent the osmiophilic tips of specialized microtriches. The bothridia of the three species have no apparent function in the absorption of food but evidence suggests that the apical pad of the myzorhynchus ofEcheneibothriumis specialized for the uptake of nutrients directly from the submucosa of the host intestine to which it is applied. Attachment and sensory roles by the myzorhynchus are also indicated.EcheneibothriumandP. pirieibothridia severely damage the host mucosal surface, while those ofA. quadripartitumdo little harm. This difference is probably associated with the size, mobility and mode of attachment of the cestodes. There are indications that the bothridia ofEcheneibothriumupset the metabolism of mucosal cells in the attachment region. The tips of the strobilar microtriches ofA. quadripartitumare shown to function in the attachment of the strobilum to the host mucosa, and in the protection of the microthrix proximal surfaces by a filtering action.
Some observations on the cuticle of the larvae of Hypoderma bovis and Hypoderma diana (Oestridae)
Authors: Kennaugh J. H.
Published: June 2009

The third-instar larval cuticles of Hypoderma bovis and H. diana and the puparial cuticle of H. bovis are described. The observations on and the descriptions of these cuticles are compared with the work of Enigk & Pfaff (1954) on H. bovis larval cuticle. The cuticles of the Hypoderma species are compared with the typical dipteran larval cuticle described by Dennell (1946) for Sarcophaga and found to approximate very closely to this basic pattern. In view of this it has been necessary to revise the terminology of the cuticular layers as originally described by Enigk & Pfaff for Hypoderma bovis. A description of the puparial cuticle and its specialized structure and the histological appearance of the pupal suture or line of weakness is given.
Hepatojarakus bandicotisp.nov. from rodents in Punjab, India
Authors: Sood M. L. , Parshad V. R.
Published: June 2009

Hepatojarakus bandicotisp.nov. has been described fromBandicota bengalensis(type host),Millardia meltada, Tatera indicaandMus musculus bactrianus. The genusHepatojarakusYeh, 1955, has been retained in the family Trichostrongylidae Leiper, 1912. This is the second record ofHepatojarakusand the first from India.
The course of infection and growth of Moniliformis dubius (Acanthocephala) in the intermediate host Periplaneta americana
Authors: Lackie J. M.
Published: June 2009

A quantitative study has been made of the relationship between Moniliformis dubius and Periplaneta americana.

1. Eggs removed from the body cavity of the worm hatch at a higher rate after dessication and after a short period of time following removal.

2. There is an exponential decline in the additional number of cystacanths recovered as the dose is increased linearly.

3. Female cockroaches are more susceptible to high levels of infection than males.

4. Direct injection into the haemocoele produces a similar recovery rate to that from oral infection.

5. Previous infection does not seem to affect the success of a superimposed infection.

6. Rates of development and growth are described.

7. The effect of the parasite on the concentration of free amino acids in the haemolymph was found to be negligible.

I would like to thank Miss S. Arnold and Mr D. Barnard for technical assistance, Mr E. Walters for help with statistical analysis, Dr D. W. T. Crompton for many helpful discussions and Dr P. J. Whitfield for reading this paper. This work has been carried out during the tenure of a Science Research Council Studentship.
Studies on molluscan schistosomiasis: An analysis of the development of the cercaria of Schistosoma mansoni
Authors: Cheng Thomas C. , Bier Jeffrey W.
Published: June 2009

Development of cercariae within intramolluscan germinal sacs is recognized to be in seven stages; in brief, these stages are: 1, germinal cell; 2, naked cell aggregate; 3, germ ball prior to elongation; 4, elongating germ ball; 5, tail bud stage; 6, tail elongation stage; and 7, fully developed cercaria.

Schistosoma mansoni cercariae at each of the developmental stages is described.

The dimensions of both germinal and somatic cells comprising the bodies of developing S. mansoni cercariae decrease with maturation.

The surfacial membrane of Stage 3 cercarial embryos is formed by a number of small somatic cells which migrate to the surface and coalesce.

The chronologic and partially synchronized development of S. mansoni cercariae is presented.

The body-tail ratio during S. mansoni cercarial development is presented.
The alleged alternation of sexual phases inKuhnia scombri, a monogenean ofScomber scombrus
Authors: Finlayson Janet E.
Published: June 2009

In 1945 Sproston stated that an alternation of sexual phases takes place inKuhnia scombri, a monogenean ofScomber scombrus, but an examination of egg-laying, the state of the sexual organs and the presence of sperms in this parasite at various times of the year have shown that there is no evidence for the existence of such a phenomenon. Sproston's observations are examined with particular reference to problems in measuring the length of the parasite and to the unreliability of using the presence or absence of eggs in the uterus as an index of femaleness.
Intraspecific and interspecific pairing of Haematoloechus medioplexus (Trematoda) and Echinostoma revolutum (Trematoda) adults in vitro, and observations on H. medioplexus lipophilic excretory–secretory products
Authors: Fried B. , Leiby D. A.
Published: June 2009

Intraspecific pairing of Haematoloechus medioplexus and Echinostoma revolutum adults and interspecific pairing of H. medioplexus and E. revoltum adults were studied in vitro at 21 ± 1 °C and 30 ± 1 °C in Petri-dish cultures containing an agar substrate and a Locke's 1:1 solution overlay. Salinity and temperature tolerance tests showed that both species survived for 24 h in a Locke's 1:1 solution at 21 ± 1 °C and 30 ±1 °C. For behaviour studies, worms were placed 2 cm apart and then observed at various intervals from 5 min to 4 h. H. medioplexus and E. revolutum showed significant intraspecific pairing at 30±1 °C, whereas only H. medioplexus paired significantly at 21±1°C. Significant interspecific pairing of H. medioplexus and E. revolutum occurred at 21 ±1 °C and 30 ±1 °C. Thin-layer chromatographic analysis showed that H. medioplexus adults released mainly free sterol, along with traces of triacylglycerols and free fatty acids into a non-nutrient medium.
A comparison of membrane-bound enzymes of the isolated brush border plasma membranes of the cestodes Hymenolepis diminuta and H. microstoma
Authors: Pappas P. W. , Narcisi Elizabeth M.
Published: June 2009

Preparations of isolated brush border plasma membrane of Hymenolepis diminuta and H. microstoma possess the following enzymatic activities: alkaline phosphohydrolase (E.C. 3.1.3.1); Type I phosphodiesterase (E.C. 3.1.4.1); ribonuclease (E.C. 3.1.4.22); adenosine triphosphatase (E.C. 3.6.1.3); and 5′-nucleotidase (E.C. 3.1.3.5). The following enzymatic activities could not be demonstrated in either membrane preparation: Type II phosphodiesterase (E.C. 3.1.4.18); cyclic adenosine-3′, 5′-monophosphate phosphodiesterase (E.C. 3.1.4.17); leucine aminopeptidase (E.C. 3.4.11.1); maltase (α-glucosidase; E.C. 3.2.1.20); and lactase (β-galactosidase; E.C. 3.2.1.23). These data generally agree with those of previous studies in which similar membrane-bound enzymes were demonstrated in intact (living) worms.
Trypanosoma (Schizotrypanum) dionisii of Pipistrellus pipistrellus (Chiroptera): intra- and extracellular development in vitro
Authors: Baker J. R. , Green Sheila M. , Chaloner Lisbeth A. , Gaborak Maria
Published: June 2009

A trypanosome identified as Trypanosoma (Schizotrypanum) dionisii Bettencourt & França, 1905, has been isolated from Pipistrellus pipistrellus (Chiroptera) in England. At least five out of eight P. pipistrelhis were infected.
2. In the blood of P. pipistrelhis, the parasite closely resembled T. (S.) cruzi. When grown in vitro in monophasic or diphasic media at 28°C, epimastigotes and trypomastigotes developed. The latter were of two types — very long, thin forms and less numerous shorter individuals.
3. The trypanosomes multiplied as amastigotes within HeLa and mouse L cells in vitro. After 6–9 days in HeLa cells at 37°C, they transformed into small trypomastigotes and emerged from the cells. Higher infection rates (up to about 4%) were obtained in cell cultures inoculated with flagellates from older monophasic cultures, which contained more of the long, slender trypomastigotes.
4. Trypanosomes also entered (or were phagocytosed by) up to 60% or more of mouse peritoneal macrophages in vitro. Multiplication occurred by binary and multiple fission of amastigotes in at least some of the parasitized macrophages and transformation into trypomastigotes was seen after 7 or more days at 37°C. Development in macrophages was less synchronous than in HeLa cells.
Immunity to coccidiosis: maternal transfer inEimeria maximainfections
Authors: Rose M. Elaine
Published: June 2009

Chicks hatched from eggs laid in the third and fourth weeks after inoculation of the hens with oocysts ofE. maximaexcreted fewer oocysts in response to a challenge inoculum ofE. maximagiven at 1 week of age than controls hatched from the eggs of uninfected hens. A λ-livetin fraction prepared from the yolks of eggs laid by hens 14–22 days after a single inoculation of oocysts ofE. maximaand injected subcutaneously into 2-week-old chicks caused a similar reduction in oocyst yield from a challenge inoculum. The serum of the donor hens, obtained at the corresponding time intervals was protective. These results confirm that immunity to infection withE. maximais, at least in part, mediated by humoral antibodies.
Fine structural changes in Eimeria tenella, from infections in chick embryos and chickens, after exposure to the anticoccidial drug robenidene
Authors: Lee D. L. , Millard B. J.
Published: June 2009

The structure of the various stages of Eimeria tenella grown in the chorioallantoic membranes of the chick embryo has been shown to be similar to the stages in the caecum of the bird.
The effects of the anticoccidial drug, Robenidine, on the fine structure of the various stages of E. tenella, grown in the chick embryo and in the caecum of the bird, have been described. The first noticeable change occurs in the endoplasmic reticulum, including the nuclear envelope, and in the Golgi complexes of all stages. The nucleus itself, and the mitochondria, do not appear to be affected by the drug until much later, and this effect is probably due to the degeneration of the cell.
It is suggested that the drug may have a direct effect upon protein metabolism of the parasite, resulting in swelling of the granular endoplasmic reticulum and Golgi complexes, or that it may have a primary effect upon some other organelle or metabolic process, and that the swelling of the endoplasmic reticulum and Golgi complexes is a secondary or tertiary phenomenon.
Enzyme variation inPlasmodium bergheiandPlasmodium vinckei
Authors: Carter R.
Published: June 2009

A study of electrophoretic forms of a selection of enzymes has been made in strains of subspecies of the rodent malaria parasitesPlasmodium bergheiandP. vinckei. Considerable electrophoretic variation of these enzymes occurred among the strains studied. On the basis of the results it was possible to identify groups of parasites within each species. While generally substantiating the classical taxonomy the identification of groups provided further information on the relationships between the subspecies.
In vitrohatching ofHymenolepis diminutaeggs inTenebrio molitorextracts and in defined enzyme preparations
Authors: Lethbridge R. C.
Published: June 2009

The results of several experiments that included variation of the pH and concentration of the extracts and analysis of the role of enzymes separated from midgut fluid by electrophoresis indicated that hatching involved two or more proteolytic enzymes that digested the cytoplasmic layer and embryophore. Amylases fromT. molitorand other sources were shown to play no part in hatching. A defined medium based on analyses of midgut fluid and containing trypsin, chymotrypsin and peptidases was shown to digest the embryophore and effect the release of hexacanths in a time comparable to that obtained withT. molitorextracts. The specificity of the enzymes attacking the cytoplasmic layer remains unknown.
Penetration gland secretion by hexacanths of Hymenolepis diminuta
Authors: Lethbridge R. C. , Gijsbers M. F.
Published: June 2009

The rate of expulsion of penetration gland material was determined from photomicrographs of Hymenolepis diminuta hexacanths stained with neutral red dye at intervals after hatching in vitro. Identical secretory rates were recorded for hexacanths incubated in either Tyrode's solution or Tyrode's solution plus an extract of the midgut of Tenebrio molitor. In both media the reduction in stained material observed in the glands after 135 min incubations was equivalent to that observed for hexacanths that had had opportunity to penetrate in vivo during the same time period. These results were interpreted as indicating that the in vivo secretory pattern was similar to that observed in vitro, and that chemical stimuli from the tissue extracts were not required to initiate secretion. Microdensitometric readings also demonstrated a quantitative decrease in dye within the glands as incubation time increased. Ultrastructural examination of the glands showed that their secretory inclusions were exported via ducts to the epithelial cytoplasm where they accumulated in discrete blebs enclosed by the surface membrane. These inclusion-filled, membrane-bounded blebs were apparently formed and released continuously until, after approximately 2 h, only a few inclusions remained in the penetration glands.
Oogenesis and fertilization in Dipetalonema viteae (Nematoda: Filarioidea)
Authors: McLaren Diane J.
Published: June 2009

Oogenesis and fertilization in the filarial worm Dipetalonema viteae have been described. The female gametes are developed from a syncytium situated at the posterior tip of the ovary. The syncytium grows along the length of the ovary as an anucleate rachis carrying the germ cells with it. In the germinal region of the ovary the rachis is a central axial structure, but in the growth region it becomes very branched. The female gametes retain their attachment with the rachis until they have become mature primary oocytes; they acquire a surface coat whilst in the growth zone of the ovary. At fertilization the successful spermatozoon produces numerous ribosomes. Residual spermatozoa are apparently destroyed by the oocyte. The fertilized oocyte divides meiotically to yield an ovum and two polar bodies. In species destined to be unsheathed in the blood the surface coat and the original oolemma separate from the surface of the ovum. A new oolemma is produced, presumably under the stimulus of fertilization.
The structure and mode of action of the posterior adhesive organ ofPseudobenedenia nototheniaeJohnston, 1931 (Monogenea: Capsaloidea)
Authors: Williams I. C. , Ellis C. , Spaull V. W.
Published: June 2009

An account is given of the structure and mode of action of the opisthaptor of the monogeneanPseudobenedenia nototheniaeJohnston, 1931, from the skin of the fishNotothenia neglecta, caught in December 1969 at a depth of 40 m offSigny Island (60° 43′ S., 45° 36′ W.), South Orkney Islands. The opisthaptor has a roughly hexagonal central loculus surrounded by a septum which is continuous with six radiating septa. It is armed with 14 marginal hooklets and three pairs of sclerites which function as anchors. The opisthaptor obtains adhesion through gripping the host's skin with the muscular rim, and through close contact by the marginal membrane. These form a water-tight seal, the surface area of which is about one-quarter of that of the ventral surface of the opisthaptor. The seal enables the opisthaptor to function as an underwater sucker. Contraction of muscles associated with the opisthaptor, in particular the extrinsic muscles, can generate a pressure difference across the wall of the opisthaptor some 50 times greater than that required to support the weight of the parasite, thus suggesting that reserves are available to resist dislodging forces such as increased water flow. The instability and tendency to slide of the sucker is counteracted by anchorage from the hooklets and sclerites. The structure and mode of action of the opisthaptor ofP. nototheniaeare discussed in relation to studies made by other authors on similar adhesive organs.
The specific immunoglobulin response in cattle immunized withTheileria parva(Muguga) stabilate
Authors: Duffus W. P. H. , Wagner G. G.
Published: June 2009

Immunoglobulin synthesis in response to experimental infection of cattle withTheileria parva(Muguga) was studied by Sephadex G 200 chromatography. Serum samples were collected for 88 days following inoculation. Indirect fluorescent antibody (IFA), complement fixation (CF), indirect haemagglutination (IHA) and immunodiffusion (ID) tests were used to detect activity againstT. parvapiroplasm antigen. There was a small and transient IgM response in the IFA test, thereafter all IFA activity was 7S Ig. A sequential production of IgM and 7S Ig CF antibodies was demonstrated. In all sera tested only IgM activity was demonstrated by the IHA test. These results are compared with those from similar studies withT. parvaand other protozoan diseases, especially in the differential immunoglobulin response shown by the contrasting results from the three serological tests.
Field studies on inhibition ofHaemonchus contortusin sheep
Authors: Waller P. J. , Thomas R. J.
Published: June 2009

The epidemiology ofHaemonchus contortuswas studied in north east England in lambs reared under field conditions with infected ewes. The parasite population was monitored by pasture larval counts, faecal egg counts and lamb postmortems. From 25 June to 11 November, eight lambs were slaughtered each month, together with eight worm-free tracer lambs. Postmortem worm counts showed that on 25 June, small numbers of adultH. contortuswere present but no inhibited larvae. However, subsequently the number of worms recovered rose rapidly to 1000–5000 and the percentage inhibition increased to 57% in July, 75% in August and virtually 100% in September, October and November. On each sampling occasion no significant differences in worm count or percentage inhibition were recorded between experimental and tracer lambs. These results suggest that neither autumn climatic effects nor host immunity were responsible for inhibition in this strain ofH. contortus.
Eimeria falciformis (Eimer, 1870) in specific pathogen free and gnotobiotic mice
Authors: Owen Dawn
Published: June 2009

The endogenous and exogenous stages of a species of murine Eimeria were examined and compared with descriptions of other species isolated from Mus musculus. Developing stages of the parasite were found in the epithelial cells of the caecum and colon. Three asexual generations were observed, the third becoming apparent on the fourth day concurrently with gametogeny. The total length of the prepatent period was 5 days. Oocysts of the coccidian, identified as Eimeria falciformis, were administered to a group of germfree mice. Despite a dose level of 1 ü 106, the coccidium was not established. Histological examination indicated the failure of the sporozoite to penetrate its host epithelium. The possible causes of this phenomenon were discussed.
Seasonal abundance of Proteocephalus ambloplitis (Cestoidea: Proteocephalidea) from largemouth bass living in a heated reservoir
Authors: Eure Herman
Published: June 2009

Proteocephalus ambloplitis was recovered from largemouth bass inhabiting different thermal regimes, ranging from normal to greater than 10 °C above normal, on the Energy Research and Development Administration's (ERDA) Savannah River Plant near Aiken, South Carolina. Possible alterations in the mechanisms initiating plerocercoid migration as proposed by Fischer & Freeman (1969) were noted. According to these authors, a rise in temperature from 4 to 7 °C and above stimulated migration of parenteric plerocercoids into the gut. The lowest water temperature recorded for the reservoir for the entire sampling period was 8·0 °C. Theoretically, this should have terminated the life-cycle of this tapeworm since migration temperature was never attained. At Savannah River, the appearance of adult tapeworms coincided with a decrease in water temperature, while the appearance of adult tapeworms in Canada was correlated with an increase in water temperature. It is postulated that the decline in water temperature in southern latitudes and the increase in water temperature in northern latitudes initiates the same response, that is, migration of plerocercoids from parenteric to enteric sites where maturation to the adult form ensues.
Schistosoma mansoni in the baboon (Papio anubis): parasitological responses of Kenyan baboons to different exposures of a local parasite strain
Authors: Sturrock R. F. , Butterworth A. E. , Houba V.
Published: June 2009

The course of infection with a local strain of Schistosoma mansoni was investigated in Kenyan baboons (Papio anubis). A single exposure to 5000 cercariae per baboon (cpb) killed five 4–8 kg baboons; a sixth survived the full 30-week post-exposure period, with suppressed egg production after week 11. Lower doses were not lethal. A single exposure to 1000 cpb gave satisfactory adult worm recoveries, high and steady faecal egg excretion, and a high tissue egg recovery, predominantly from the large intestine. A similar but less consistent picture was obtained with a single exposure to 200 cpb. Baboons receiving 5 monthly exposures of 200 cpb (1000 cpb total) showed some evidence of the development of protective immunity. Three animals showed patterns resembling those for 200 and 1000 cpb. The other 3 had suppressed egg production (faecal and tissue) indicating, perhaps, some immunological process. They also had an abnormally high percentage of eggs in the liver.
Methods in coccidiosis research: separation of oocysts from faeces
Authors: Ryley J. F. , Meade R. , Hazelhurst Judith , Robinson Thelma E.
Published: June 2009

Factors which may be important in the large-scale extraction of coccidial oocysts from faeces have been investigated with Eimeria tenella. Age of bird, inoculum, feeding status at the time of inoculation, period of collection, feeding status during collection, collection medium, homogenization and sieving, flotation, washing, sporulation and further purification have all been considered. The aim has been to establish a method to produce the maximum number of oocysts of a required degree of purity and viability, with the expenditure of the minimum amount of physical effort, time, animals and chemicals. In our method, groups of chickens 3–4 weeks of age are inoculated with 5000 oocysts of E. tenella and food is supplied ad lib. Over the period 5–8 days after inoculation, faeces are collected in trays containing 2% (w/v) potassium dichromate solution, while food intake is restricted. The faecal material is homogenized, passed once through 40 and 100 mesh sieves, centrifuged and the oocysts recovered from the sediment by 3 flotations in saturated salt solution. Following washing, oocysts are sporulated by forced aeration at 30°C and may be further purified by hypochlorite treatment, or passage in 5% Tween 80 solution through a glass bead column followed by sucrose density gradient centri-fugation. Routine passages along these lines over a 5 year period have given a recovery of 46% of the oocysts excreted by over 7000 birds.
Genetic control of immune responses to parasites: selection for responsiveness and non-responsiveness to Trichuris muris in random-bred mice
Authors: Wakelin D.
Published: June 2009

Populations of Schofield strain, random-bred mice were shown to have a bimodal variation in ability to bring about immune expulsion of the nematode Trichuris muris. This variation was genetically determined and independent of the size of infection experienced. The proportion of mice unable to achieve worm expulsion (non-responders) was relatively constant in various populations of the strain but was increased by selective breeding from mice of known status. Crosses made between non-responder and responder mice produced progeny that were almost all (92%) of responder phenotype, showing that the ability to achieve worm expulsion was inherited as a dominant characteristic. It is suggested that the genetic control involves a small number of genes; the possible immunological mechanisms by which control is mediated are briefly discussed.
Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat ofTrypanosoma brucei
Authors: Cross G. A. M.
Published: June 2009

Soluble glycoproteins have been purified from a series of clones ofTrypanosoma brucei427. Each clone yielded a characteristic predominant glycoprotein which induced clone-specific immunity to trypanosome infection in mice. These glycoproteins were shown by specific labelling and enzyme digestion of cells to be the major components of the trypanosome surface coat. Each glycoprotein consisted of a single polypeptide chain having an apparent molecular weight of 65000 (as measured by SDS-polyacrylamide gel electrophoresis) and containing around 600 amino acid and 20 monosaccharide residues. Preliminary structural studies indicated large changes in amino acid sequence dispersed over a considerable length of the polypeptide chain. Proteolytic activity was demonstrated in semi-purified trypanosome extracts, providing one reason for the heterogeneity sometimes observed in surface glycoprotein antigen preparations.
In vitroisolation ofPlasmodium knowlesimerozoites using polycarbonate sieves
Authors: Dennis E. D. , Mitchell G. H. , Butcher G. A. , Cohen S.
Published: June 2009

A culture chamber fitted with a polycarbonate sieve has been used to isolatePlasmodium knowlesimerozoites as they are released from schizonts. A 3 μm pore-size sieve allows passage of normal erythrocytes and red cells containing rings and trophozoites and can be used to concentrate schizonts from a mixed cell population. A 2 μm pore-size sieve retains normal and parasitized cells and provides uncontaminated merozoites in high yield (5 × 1010merozoites per ml schizonts). Merozoite viability diminishes rapidly during 30 min after isolation. These preparations should prove valuable for studies of the biochemical, physiological and antigenic properties of this transient extracellular phase of the malaria parasite.
Studies on Eimeria grenieri in the guinea fowl (Numida meleagris)
Authors: Long P. L. , Millard B. J.
Published: June 2009

Eimeria grenieri was isolated from intensively reared guinea fowl in Britain. The oocysts had average dimensions of 21·09 × 15·48 μm and a small micropyle. Three generations of schizonts were found in the small intestine. The first mature schizonts were found in the upper intestine 30 h after inoculation. Second-generation schizonts were seen 48–80 h and third-generation schizonts were present 80–96 h after inoculation. These schizonts were found in the middle and lower small intestine. It was confirmed that gametogony of this species occurs only in the caeca. The pre-patent time was 112 h and the reproductive index from a dose of 6 × 102 oocysts was 8 × 104. Doses of between 1 × 104 and 1 × 106 caused severe depression of body weight gain. Immunity to re-infection developed rapidly. Sulphaquinoxaline at a dose of 0·04% in the drinking water given after inoculation was effective in reducing the pathogenic effects of the disease. Robenidine given in the food at a concentration of 16·5 ppm (50% of the recommended concentration for chickens) was effective in preventing disease caused by E. grenieri.

The endogenous life-cycle of E. grenieri was completed in the chorioallantoic membrane of developing chicken embryos.
The immune respone of plaice (Pleuronectes platessaL.) to the metacercariae ofCryptocotyle linguaandRhipidocoytle johnstonei
Authors: Cottrell B.
Published: June 2009

The humoral immune response of plaice to infestations of selected metacercariae was studied. Precipitating antibodies to bothCryptocotyle linguaandRhipidocotyle johnstoneiwere demonstrated using agar geldiffusion techniques. Immunochemical investigations of these antibodies indicated they were macroglobulins, resembling immunaglobulin M(IgM) of mammals. The rate and magnitude of antibody production by the host was determined by the ambient temperature
Desiccation survival of larval and abult stages of the plant parasitic nematodes,Ditylenchus dipsaciandD. myceliophagus
Authors: Perry R. N.
Published: June 2009

The effect of different relative humidities on the survival of individual larvae and adults ofDitylenchus dispasciand D.myceliophagushas been examined; experiments were carried out at 5 and 18°C with D.myceliophagusand at 18°C with D.dipsaci. Survival of both species was enhanced when they were dried at high humidities and, for D.myceliophagus, by the lower temperature. The survival of all stages of D.myceliophaguswas poor. Generally it was expressed in minutes only; 4th-and 3rd-stage larvae, however, were marginally better at surviving drying than adults and much better than 2nd-stage larvae.

Although the 4th-stage larva of D.dipsaciwas overwhelmingly superior to all other stages, the 3rd stage, and to a lesser extent, the adult of this species also showed remarkable powers of survival to desiccation. In general, survival of 4th-, 3rd- and 2nd-stage larvae could be expressed in weeks, days and minutes respectively; for adults, survival was expressed in hours at relative humidites under 50% but in days at higher relative humidites.

The results are discussed in relation to the survival value of the aggregations formed by these species; the validity of the term ‘resistantstage’ as applied to the 4th-stage larva of D.dipsaciis assessed.
Antigenic analysis of a variant-specific component of Trypanosoma brucei brucei: localization on the surface coat with labelled specific antibodies
Authors: Fruit J. , Afchain D. , Petitprez A. , Meirvenne N. Van , Ray D. Le , Bout D. , Capron A.
Published: June 2009

The nature of antigens present on the surface coat of Trypanosoma brucei brucei (serotype AnTat–1) trypanosomes has been investigated by light and electron microscopy using indirect immunofluorescence and immunoenzymatic labelling techniques. The use of a monospecific anticomponent V serum has shown that the variant-specific antigen, component V, is the major constituent of the surface coat. Antigens of heterologous serotype, of culture form trypanosomes, of host serum proteins or host red blood cells were not demonstrated on the surface coat.
Intermittent egg release byAspiculuris tetrapterain mice
Authors: Phillipson R. F.
Published: June 2009

In order to study egg release byAspiculuris tetrapteratotal faecal collections from infected mice were made every 1½ h throughout successive 24 h periods. This was done with the aid of a histokinette machine. The cage containing the mice was suspended from one of the arms of the machine and every 1½ h the cage was moved on by the machine to the next adjacent collecting dish. The faecal pellets passed were counted and then used for flotation egg counts.

It was found that eggs were not released steadily and continuously and, in the case of the worms in an isolated mouse, egg output was clearly intermittent. Egg production did not appear to vary with the faecal production of the host in a consistent way but with two groups of 8 mice it was highest when faecal production was at its peak shortly before dawn. For the groups of 8 mice the concentration of eggs per faecal pellet was also highest at this time. In two experiments with an individual mouse, however, the egg counts fell to zero at dawn before the level of faecal production became reduced.

It is suggested therefore that egg output by femaleA. tetrapteramay be stimulated by the altered physiological state of the host associated with feeding or general activity.
Eimeria stiedaiin rabbits: the presence of an oocyst residuum
Authors: Norton C. C. , Catchpole Janet , Elaine Rose M.
Published: June 2009

Observations on 5 different isolates ofEimeria stiedaifrom pure infections in laboratory-reared rabbits have confirmed the presence of an oocyst residuum. This structure was seen in 89–100% of the oocysts in cultures prepared both from the liver and from the faeces at different times during the patent period. The residuum consisted of 1–7 or more granules situated centrally in the oocyst and partially concealed by 4 sporocysts. The differential diagnosis ofE. stiedaiandE. coecicolais discussed.
Monoamine oxidase in adult Hymenolepis diminuta (Cestoda)
Authors: Moreno M. Sanchez , Barrett J.
Published: June 2009

A membrane-bound monoamine oxidase (EC 1.4.3.4) was demonstrated in homogenates of Hymenolepis diminuta. The enzyme oxidized a variety of biologically active amines (in decreasing order: dopamine, adrenaline, noradrenaline, tryptamine, tyramine, octopamine), there was, however, no activity with 5-hydroxytryptamine or benzylamine. No diamine oxidase (EC 1.4.3.6) could be detected in H. diminuta (using histamine, cadaverine or putrescine as substrates). The monoamine oxidase from H. diminuta was not inhibited by azide, hydroxylamine or semicarbazide, but was inhibited by cupferron, α-α dipyridyl and iodoacetamide, and by the specific monoamine oxidase inhibitors pargyline, nialamide and iproniazid. Several anthelmintics were also found to be inhibitors of monoamine oxidase. The possible roles of monoamine oxidase in H. diminuta are discussed.
Life-cycle of Isospora ohioensis in dogs
Authors: Dubey J. P.
Published: June 2009

The life-cycle of Isospora ohioensis in dogs is described. Eight dogs were killed 6, 16, 24, 48, 72, 96, 114 and 120 h after feeding 106I. ohioensis sporocysts to each. First divisional stages occurred in the jejunum at 48 h post-inoculation (p.i.). At 48 h, zoites occurred in pairs in parasitophorous vacuoles of surface epithelial cells of the jejunum. The parasitophorous vacuoles were 7–9 × 6 μm and the zoites were 7–9 × 2·5 μm in sections. At 72 h, uninucleated zoites, multinucleated zoites and meronts containing fully formed merozoites occurred in surface epithelial cells of the jejunum. At 96, 114 and 120 h asexual multiplication occurred throughout the small and large intestine, mostly in the ileum. The number of asexual generations was not determined. At least 2 structurally distinct meronts were identified at 96–120 h p.i. Type I meronts contained larger merozoites (11 × 3 μm) than those (7·5 × 1·5 μm) in Type II meronts. Meronts were merozoite-shaped and contained up to 8 nuclei. Uninucleated, binucleated and multinucleated zoites occurred within the same parasitophorous vacuole. Gamonts occurred in surface epithelial cells of the small intestine, caecum and colon, but predominantly in the ileum, 96–120 h p.i. Macrogamonts were 13–17 × 11–12 (14·5 × 12·8) μm in sections and 21–26 × 17–25 (21·7 × 17·6) μm in smears. Microgamonts were 13–17 × 8–15 (15·3 × 11·4) μm in sections and 24–30 × 15–24 (27 × 19) μm in smears and contained up to 50 microgametes. The cycle was also studied in 6 dogs killed 6, 12, 24, 48, 96 and 120 h after feeding tissues of laboratory mice that had been infected with I. ohioensis oocysts 17 days earlier. Stages were not seen in the dogs killed at 6 and 12 h p.i. Asexual and sexual stages were structurally similar in size and location to the oocyst-induced cycle but their development was faster by 24 h in the mouse-induced cycle. Extra-intestinal stages were not found in sections of mesenteric lymph nodes, spleen, lung, liver, heart, skeletal muscle and brain. However, biological evidence indicated that I. ohioensis invaded the spleens and mesenteric lymph nodes of dogs fed oocysts.
A suggested terminology for populations of coccidia (Eimeriorina), particularly of the genus Eimeria (Protozoa: Apicomplexa)
Authors: Joyner L. P. , Canning Elizabeth U. , Long P. L. , Rollinson D. , Williams R. B.
Published: June 2009

A short list of terms has been compiled which provides for the discussion of variation of coccidia of the genus Eimeria at infrasubspecific levels. Based upon this list, guidelines are given for the designation of strains and lines.
The development of the tapeworm Diphyllobothrium latum (L. 1756)(Cestoda; Pseudophyllidea) in its definitive hosts, with special references to the growth patterns of D. dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1827)
Authors: Andersen Karin
Published: June 2009

When Diphyllobothrium latum develops from larva to adult in a definitive host, it first sheds the entire larval ‘body’ before growth of an adult strobila starts. This process of shedding off the entire larval abothrial extremity, piece by piece, takes about 48 h. By this time the larva has usually reached the anterior third of the small intestine of the host. D. dendriticum and D. ditremum develop quite differently, although exhibiting similar anterior migrations. In these two species the larvae develop directly into adults without the larval ‘bodyRsquo; first being shed. The implications of the observed differences in growth pattern between these three species of Diphyllobothrium to the classification of diphyllobothriid cestodes is discussed briefly.