bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on carbohydrates in tissues and coenurus fluid of larvalTaenia multicepsfrom normal and alloxanized mice
Authors: Esch Gerald W.
Published: June 2009

Results of the present study indicate that a wide range in coenurus fluid glucose concentration occurs among larvae ofTaenia multiceps. Further, a definite correlation exists between bladder size and glucose concentration in the coenurus fluid; larger bladders have greater glucose concentration per unit volume of coenurus fluid. Based on analyses of bladder fluid glucose following alloxan induced hyper-glycaemia, an abrogation of the established size-coenurus fluid glucose concentration occurred. A diabetic state did not alter glycogen concentration in the tissues or lactic acid levels in the fluids of the same coenuri. The functional significance of bladder fluid glucose in maintaining tissue glycogen at constant levels is briefly discussed.

I wish to acknowledge Dr George Lauff, Director, W. K. Kellogg, Biological Station, for constructive criticism of the manuscript and for providing facilities and equipment during the summers of 1966 and 1967.
A New Cestode, Taenia rileyi n.sp., from a Lynx
Authors: Loewen Solomon L.
Published: June 2009

From the small intestine of a lynx, Lynx canadensis, killed in the vicinity of Minneapolis, Minnesota, four strobilae and two fragments of an undescribed taenioid cestode were recovered. The largest of these tapeworms, which is the only one containing segments in all stages of development, measures 31 cm. in length and contains 253 proglottids; the other three strobilae measure 8, 26 and 30 mm. in length, respectively. The two fragments, one consisting of three and the other of eight ripe proglottids, apparently are segments from the largest one of these four strobilae.
Anin vitrostudy of the effect of oxygen tension upon the motility ofNippostrongylus brasiliensis
Authors: Alphey Thomas J. W.
Published: June 2009

An activity cell apparatus to facilitate quantitative measurements of motility of small nematodes in saline is described. The effects of salines with a pO2either greater than 120 mmHg or less than 12 mmHg upon the motility of adultN. brasiliensisfemales was studied. The worms were found to require an oxygen tension greater than 12 mmHg to be able to maintain their motility.

I am grateful to Professors J. Brough and D. Bellamy for providing the facilities during the course of this study. I should also like to thank Dr R. A.Hammond for his supervision, help and criticism throughout the project, and Mr C. Welsby for his technical assistance in the construction of the activity cell.

This work was carried out during the tenure of a Scientific Research Council Studentship.
The dynamics of the host-parasite relationship
Authors: Donald A. D. , Dineen J. K. , Adams D. B.
Published: June 2009

An experiment has been conducted to examine the effects of discontinuous infection with H. contortus in sheep on the development of resistance to infection. When sheep were given four doses of 3000 larvae at fortnightly intervals and these sensitizing infections were removed on day 56, there was no evidence of resistance at that time nor of any residual effect of the sensitizing infections on the response to challenge at day 140. When, however, the sensitizing infections were permitted to persist until day 132, there was strong resistance to the establishment of a challenge infection whether or not the sensitizing worm burden was removed prior to challenge, and, in the case of superimposed challenge, resistance was coupled with rejection of most of the sensitizing population. When a single infection with 3000 larvae was followed 22 days later with a further single dose of 3000 larvae, there was no evidence of resistance whether or not the first infection was removed with anthelmintic. If the interval between two doses of 3000 larvae was extended to 76 days there was resistance to the establishment of the second dose if this was superimposed on the first, but not if the first infection was removed 8 days prior to the second dose.

It is suggested that the manifestations of resistance appear in a sequence of (i) resistance only to a superimposed infection, followed by (ii) resistance to a challenge infection in the presence or absence of a previously existing worm burden, coupled in the former case with rejection of much of the existing population. This sequence could be related crudely to a product of larval dose and time. Although larval dose and time were to some extent confounded in the design of the experiment strong resistance was associated with prolonged uninterrupted infection.
Systems analysis of a host-parasite interaction
Authors: Ractliffe L. H. , Taylor H. M. , Whitlock J. H. , Lynn W. R.
Published: June 2009

Most epidemiological models assume that disease is the inevitable outcome of infection (see Bailey, 1957). Yet as Dubos (1965) has said; ‘Throughout nature, infection without disease is the rule rather than the exception’. There are, in fact, many diseases whose distribution cannot be explained solely by a consideration of the probabilities of host parasite encounters. In these cases, a diseased state is only one possible outcome of an interaction between parasite phenotypes, host phenotypes and the external environment. Haemonchosis is an example of such a disease and has been studied extensively in quantitative terms (see Whitlock & Georgi, 1968).
Prototransversotrema steeri gen.nov., sp.nov. (Digenea: Transversotrematidae) from a South Australian fish
Authors: Angel L. Madeline
Published: June 2009

Prototransversotrema steeri gen.nov., sp.nov. is found under the scales of the mullet, Aldrichetta forsteri, a euryhaline fish.

It is distinguished from Transversotrema Witenberg, the only other genus of the family Transversotrematidae by the possession of an oral sucker as well as a pharynx. This necessitates alteration of the family diagnosis.

Knowledge of the life-histories of Transversotrema spp. is summarized. The so-called ‘metacercariae’ found under the scales of freshwater and euryhaline fish are regarded as adults. When they have no eggs or only one egg they have probably developed in a fish which is not the normal host.

P. steeri escapes from under the scales of the fish shortly after the latter is caught. It is suggested that this habit may account for the small number of species known in the family.
Enzyme electrophoresis and speciation of Schistosoma intermediate hosts
Authors: Coles G. C.
Published: June 2009

1. Enzyme electrophoretic patterns from populations of snails, intermediate hosts of Schistosoma, have been examined.

2. Esterase patterns (α-naphthyl butyrate as substrate) have been used to differentiate snail populations of B. africanus and Biomph. pfeifferi.

3. Malate, β-hydroxybutyrate and α-glycerophosphate dehydrogenases may be of use in some cases to distinguish between species, e.g. B. africanus v. B. ugandae and Biomph. sudanica v. Biomph. pfeifferi.
Experimental studies on the chemosterilization of Schistosoma mansoni
Authors: Davies Pamela , Jackson Harold
Published: June 2009

Treatment of mice infected with S. mansoni by various sterilants effective against male rodents produced phases of inhibition of schistosome oviposition assessed by miracidial counts. In the treated worms, besides apparent disappearance of the testes, marked involution of ovarian tissue occurred. The gonads of both male and female worms seem to be directly affected by the antifertility substances. It is suggested that gamete production in both sexes follows similar lines in contrast to the finite reservoir of meiotic oocytes in mammals.
The influence of pCO2 and the rate of shaking on the ecdysis of infective Haemonchus contortus cayugensis larvae
Authors: Slocombe J. Owen D. , Whitlock J. H.
Published: June 2009

Infective Haemonchus contortus cayugensis larvae were stimulated to exsheath in 0·02 m-Na2B4O7. 10H2O saturated with varying concentrations of CO2. Larvae stimulated to exsheath with 40% CO2 gave a higher exsheathment rate than larvae stimulated with 99·95 % CO2. There was a linear relationship between the exsheathment rate and the shaking rate over the range from 40 to 100 c/min when the larvae were stimulated to exsheath with 99·95 % CO2.
The effects of larval age and cold storage on the ecdysis of infective Haemonchus contortus cayugensis larvae
Authors: Slocombe J. Owen D. , Whitlock J. H.
Published: June 2009

Infective Haemonchus contortus cayugensis larvae were harvested from faecal cultures, cleaned and stored at 4°C. By means of small sample runs, exsheathment rates were determined for batches of clean larvae prior to and during storage. The larvae were stimulated to exsheath at 40°C in 0·02 m-Na2B4O7. 10H2O into which a gas mixture of 40% CO2–60% N2 was bubbled. A 20 and 60 min exsheathing time produced some and no decrease in exsheathment rates respectively for freshly cleaned unstored larvae and larvae stored 1–12 weeks. In all instances there was a reduction in the exsheathment rate 24 h after the larvae were placed in cold storage. This was considered a result of a cold shock from which the larvae did not recover until after the fourth day.
The regulation of populations ofOstertagia ostertagiin calves
Authors: Michel J. F.
Published: June 2009

The course of the worm burdens of calves infected daily with larvae ofOstertagia ostertagiat five different rates was studied by making post-mortem worm counts on groups of calves killed after experiencing infection for different periods of time.

The relationship between worm numbers and infection rates together with evidence that a turnover of worms occurred, led to the conclusion that burdens of adult worms were regulated primarily by a loss of worms at a rate proportional to the number present.

Further, estimates based on the number of developing fourth-stage larvae indicated that the proportion of the larvae administered which became established decreased gradually as the experiment progressed.

At very low infection rates, the rate of turnover of the worms was slower than at high infection rates but in all groups it remained constant through the 6 months duration of the experiment.

The development of a small proportion of the larvae administered was arrested at the early fourth stage. At the highest infection rate used, the proportion of worms that became inhibited was somewhat greater.
Studies on the distribution and site location ofNippostrongylus brasiliensiswithin the small intestine of laboratory rats
Authors: Alphey Thomas J. W.
Published: June 2009

The distribution ofN. brasiliensiswithin the small intestine of rats, following a primary infection, is described.

The fourth stage larvae were found to inhabit the sections later parasitized by the adult population.

Both the larval and adult worms were found to be confined to the anterior half of the small intestine. This aggregation is believed to be under the influence of stimuli (factor(s) 1), present in the lumen of the host gut.

The adult worms also clumped within the already confined worm population. This behaviour is thought to be due to intrinsic behaviour patterns of the worm, sexual attraction and thigmokinesis.

Larval and adult worms were surgically transferred to points, at varying distance from the ‘normally’ inhabited region, in the small intestine of fresh recipient rats. The resulting migratory behaviour of the worms was studied.

The worm populations resulting from both the larval and the adult transfers showed the ability to recognize that they were in the wrong position of the small intestine and to be able to orientate, migrate and locate the ‘normal’ site.
Malarial S-antigens from man and owl monkey infected with Plasmodium falciparum
Authors: Wilson R. J. M. , Voller A.
Published: June 2009

Owl monkeys infected with the Malayan Camp strain of Plasmodium falciparum were found to have malarial antigens in their serum at the height of infection. The antigens were identical with certain malarial S-antigens present in the sera of West African (Gambian) children acutely infected with P. falciparum. The infected owl monkey thus appears to provide an experimental model which is relevant to the study of the serology of human malaria.
Scanning and transmission electron microscopy ofEimeria maximamicrogametogenesis
Authors: Ball S. J. , Pittilo R. M. , Joyner L. P. , Norton C. C.
Published: June 2009

The structure and development of microgametocytes ofEimeria maximafrom chicks killed during the 6th day of infection were examined using transmission and scanning electron microscopy. Initially, nucleoli disappear and the surface of the microgametocyte invaginates. This is followed by a condensation of the chromatin which then lies at the periphery of the nuclei. Concurrent with this, the flagella are formed and they project into the parasitophorous vacuole and internal invaginations. Eventually, the nuclei become more dense and are seen to protrude from the periphery of the gametocyte. The surface view of mature microgametocytes consists of a large number of closely packed flagella.
Invasion of skin by larvae of the cat hookworm,Ancylostoma tubaeforme
Authors: Matthews B. E.
Published: June 2009

A modification of the ‘floating raft’ method ofin vitropenetration study is described. This allows replication of results and additional conveniences in operation. Filter paper membranes have shown characteristics similar to those of skin and have been used for quantitative studies. A method of digesting penetrating larvae from skin has been used to reduce the variability inherent in whole skin. Neither chloroform soluble skin products nor gravity were found to have a significant effect on the number of larvae entering membranes. Exsheathment of larvae was not essential prior to penetration and no specific stimuli for exsheathment appear to be necessary. Scanning electron micrographs have shown that entry may be by either hair follicles or desquamations of the stratum corneum. No evidence of enzymic activity during the invasion process has been found so far and the results suggest that a mechanical rather than chemical system obtains.
Trypanosoma cruzi– milk transmission of infection and immunity from mother to young
Authors: Miles M. A.
Published: June 2009

Trypanosomes are consistently present in the milk of lactating mice with primary phaseT. cruziinfections (Peru strain). The infection is transmitted to the young, although rarely, mainly due to the difficulty of establishing infection via the oral route. Lactating females which had recovered from the primary phase ofT. cruziinfection consistently transferred antibody to their young during suckling. The antibody in the serum of the young and milk of the mother was detectable by the indirect fluorescent antibody technique. In the case of the Peru strain the presence of antibody transferred to the young in this way correlated with very good protection againstT. cruzi. Antibody transferred to the young was no longer detectable 6 weeks after birth. The indirect fluorescent antibody technique using bloodform antigen proved specific and highly sensitive throughout, giving prolonged and comparably high titres in mice infected with chronic and acute strains ofT. cruzi.
Distribution of acephaline gregarines of British earthworms and their comparison with those of other neighbouring European countries
Authors: Segun A. O.
Published: June 2009

Some monocystids of British earthworms are widely distributed, occurring in hosts which were collected from different parts of the country, whereas others are localized or irregularly distributed.
Only nine of the 45 monocystids identified from British earthworms have been reported from similar hosts collected from France, Germany and Sweden. Fourteen others occur in similar hosts collected from one or two of the continental countries and the remaining 22 monocystids appear to be completely absent from continental earthworms.
Ultrastructure of the embryonic syncytial epithelium in a cestode Hymenolepis diminuta
Authors: Rybicka Krystyna
Published: June 2009

The embryonic epithelium in Hymenolepis diminuta appears in the early preoncosphere stage. Inside the embryo there is a binucleate cell connected by a cytoplasmic strand with an epithelial layer spreading over the embryonic surface. After the embryo has become covered by tine epithelium the latter delammates into three layers. A basal layer resting on the basal lamina accumulates dense bodies. These bodies are spheroid and membrane-bound in the early embryo. In the late preoncosphere stage rodlike bodies remain in the basal epithelial layer. The basal membrane forms long invaginations into the basal layer. The intermediate epithelial layer is rich in polysomes and it is postulated that secretes extracellular material which cements the intermediate and peripheral layers and the ‘oncospheral membrane’. The continuity in embryonic, larval and adult cestode epithelium is discussed.
Self-cure of Haemonchus contortus infections under field conditions
Authors: Allonby E. W. , Urquhart G. M.
Published: June 2009

The phenomenon of self-cure, as it occurred under field conditions in East Africa, was studied in Merino sheep infected with Haemonchus contortus. The onset of self-cure, as judged by a dramatic fall in faecal egg counts, was found to be simultaneous in sheep grazing on infected pasture and in sheep grazing on parasite-free pasture. Furthermore the results of autopsies carried out before and after self-cure showed that a marked and equal loss of adult worm burdens had also occurred. These results indicate that self-cure of H. contortus infections under natural conditions occurs in the absence of reinfection and is apparently non-immunological in origin. Since the phenomenon was always associated with a period of significant rainfall, it is suggested that new growth of pasture may be a significant aetiological factor.
The effect of various periods of infection with the nematode Haemonchus contortus on the development of the nematode Nematodirus battus
Authors: Mapes C. J. , Coop R. L.
Published: June 2009

A comparison was made between 14-day-old populations of Nematodirus battus from single infections and from those which developed concurrently with Haemonchus contortus from the day of infection and from days 5 and 10 after infection. The numbers of Nematodirus fell with decreasing length of exposure to Haemonchus and were negatively correlated with the numbers of Haemonchus. The percentage of the populations of Nematodirus in the adult stage and the mean worm lengths fell with increasing length of development with Haemonchus, the lowest values being found in infections which developed concurrently with the abomasal worm for the full 14 days (days 0–14). Mean Nematodirus worm lengths were negatively related to abomasal pH and Na+ levels in populations which were concurrent with Haemonchus for the last 9 days (days 5–14) and for the full 14 days of development studied. Nematodirus egg capacity also fell with exposure to Haemonchus, but was lower in the worm populations exposed for the last 9 days than in those exposed for 14 days. Egg capacity was related to abomasal electrolyte levels in populations which had developed concurrently with Haemonchus for the last 9 days and for the full 14 days. Significant differences between the population parameters of Nematodirus from the proximal and middle third of the small intestine were only found in the single Nematodirus infections and in those which were concurrent with Haemonchus for the last 4 days (days 10–14). The differences in the populations of Nematodirus were related to the probable changes in alimentary conditions affected by the different periods of concurrent infections of Haemonchus. It was suggested that the alimentary changes may have caused the loss of adult Nematodirus and have influenced the growth, development and reproductive capacity of the intestinal worm by acting upon the fourthand fifth-stage larvae.
Trypanosoma bouffardiof West African Ploceidae (Aves)
Authors: Molyneux D. H.
Published: June 2009

Trypanosoma bouffardiLeger & Blanchard, 1911, is described from naturally infectedLagonosticta s. senegala, Estrilda b. bengalus, Vidua chalybeata, Estrilda t. troglodytesandAmadina f. fasciata, all of which are new host records for Nigeria;Vidua chalybeatais a new host record for trypanosomes.

There was no significant morphological difference between populations of this trypanosome in the various natural and experimental vertebrate hosts.

T. bouffardiwas transmissible to nine species of Ploceidae belonging to the three subfamilies Estrilinae, Ploceinae and Viduinae; but not toPycnonotus barbatus, chickens or pigeons.

The parasitaemia produced by infections ofT. bouffardireached 4·1 × 105parasites/mm3of blood.

Reproduction of the trypanosomes was synchronous and discontinuous and occurred in the blood by unequal binary fission of trypomastigotes. Occasionally longitudinal equal binary fission of trypomastigotes also took place. There was no concentration of dividing forms in the tissues.

T. bouffardidid not grow on NNN medium although it has been grown for a short time on the medium described by Yesufu (1970).
Larvae of Dichetophora biroi (Kertesz, 1901) (Diptera: Sciomyzidae) feeding on Lymnaea tomentosa (Pfeiffer, 1855) snails infected with Fasciola hepatica L.
Authors: Fontana P. G.
Published: June 2009

An experiment was performed to test whether the larvae of the sciomyzid fly Dichetophora biroi are able to ‘recognize’ and reject Lymnaea tomentosa snails infected with Fasciola hepatica.

The analysis of the results indicates that the larvae do not show any obvious preference when given the simultaneous choice of non-infected and infected snails, and also that, under laboratory conditions, the latter are not more vulnerable than the former to the larval predation.

I wish to express my sincere gratitude to Dr R. P. Herd for his help and encouragement during this work. I am also grateful to Professor C. O. Berg, Cornell University (U.S.A.); Dr J. J. Lynch, C.S.I.R.O. Pastoral Research Laboratory, Armidale (N.S.W.) and Dr M. D. Rickard, University of Melbourne, for valuable advice and fruitful discussions. Dr J. A. Thomson, University of Melbourne, critically read the manuscript.
A comparison of the effects of infection with Eimeria maxima and dietary restriction on weight gain, plasma metabolites and liver glycogen in the immature fowl, Gallus domesticus
Authors: Chapman H. D. , Fernandes D. L. , Davison T. F.
Published: June 2009

The effects of Eimeria maxima or restricted pair-feeding on weight gain, plasma concentrations of protein, glucose, free fatty acids (FFA) and uric acid and liver glycogen were compared in immature fowl. Food intake/kg body weight and weight gain decreased during the acute phase of infection (days 5–7) while weight loss was prolonged for an extra day compared with pair-fed birds. During recovery, food intake/kg body weight of infected birds was greater than that of non-infected controls but there was no evidence for an increase in growth rate compared with controls when body weight was considered. Growth rate of pair-fed birds was greater than that of infected birds during recovery, indicating their better use of ingested food. Liver glycogen and plasma protein concentration were decreased during the acute phase of infection but the concentrations of plasma glucose, free fatty acid (FFA) and uric acid were not affected. In pair-fed birds liver glycogen was depleted, concentrations of plasma glucose and uric acid decreased and FFA increased, and these changes persisted for the remainder of the experiment. The findings are similar to those in birds whose food has been withheld and were probably due to the pattern of food intake imposed by the experimental protocol. It is concluded that the metabolic differences between infected and pair-fed birds are of doubtful significance.
The cell surface ofPlasmodium gallinaceum sporozoites: microelectrophoretic and lectin-binding characteristics
Authors: Turner D. P. , Gregson N. A.
Published: June 2009

The cell surface properties ofPlasmodium gallinaceumsporozoites have been investigated by means of microelectrophoretic and lectin-binding studies. Their electrophoretic mobility has been measured as a function of pH, the results suggesting qualitative and quantitative differences in the surface ionogenic groups between sporozoites from mature oocysts and those from salivary glands. Reaction of sporozoites with citraconic anhydride produced a small but significant increase in mobility, whereas 5,5-dithio-bis-(2-nitrobenzoic) acid had no effect on mobility; thus there appear to be amino groups but not –SH groups at the surface of sporozoites. Treatment of sporozoites with trypsin considerably reduced their mobility and suggests that a significant proportion of the cell surface charge is associated with protein. Incubation with neuraminidase, however, had no effect on sporozoite mobility and indicates that sialic acid residues, responsible for much of the negative charge associated with mammalian cells, are probably not present on the cell surface of sporozoites. Evidence for the presence of carbohydrates on the cell surface membrane of sporozoites was sought using fluorescein isothiocyanate–Concanavalin A. Results demonstrated that ligands similar to α-D-glucose and α-D-mannose are not present in an exposed or reactive form on the cell surface membrane ofP. gallinaceumsporozoites.
Life cycle of a new echinostome from Egypt, Echinostoma liei sp.nov. (Trematoda: Echinostomatidae)
Authors: Jeyarasasingam U. , Heyneman D. , Lim Hok-Kan , Mansour Noshy
Published: June 2009

A 37-spined Egyptian echinostome, Echinostoma liei sp.nov., is described in adult and larval stages. The parasite develops readily in the laboratory in chicks and ducklings, hamsters and rats. Its natural final host in or near irrigation ditches of the Nile delta involves the roof rat, Egyptian giant shrew and aquatic bird hosts. Developmental forms are described from infection of the NIH strain of Biomphalaria glabrata in the laboratory. B. alexandrina, is infected in the normal habitat in Egypt and contains both developmental stages in the heart or aorta and the hepatopancreas, and metacercariae encyst in the pericardium and kidney. E. liei sp.nov. is one of six very similar species characterized by 37 collar spines with a pattern of (3 + 2) corner spines in each lappet, six laterals on each side, and 15 dorsals in alternating rows; two pairs of dorsoventral and one small pair of ventro-lateral finfolds on the cercarial tail; and rodlike cystogenous material filling the cercarial encystation glands. In addition to distinctive intermediate-host specificity, differentiating characteristics of E. liei cercariae include presence of six sets of three flame cells each per side (total 36), seven oesophageal cells, eight penetration gland outlets on the dorsal lip of the oral sucker, and an absence of paraoesophageal gland cells as determined by intravital dyes. Significance of these and other cercarial traits is emphasized to aid in defining highly similar, but none the less distinct, sibling species.
A rational approach to the serial culture of malaria parasites: evidence for a deficiency in RNA synthesis during the first cyclein vitro
Authors: Trigg P. I. , Gutteridge W. E.
Published: June 2009

When ring-stage parasites are grown to the late trophozoite stagein vitro, the incorporation of [3H]adenosine into parasite DNA and RNA is in the ratio of ~ 1:1·5 and not 1:4 as expected from direct biochemical analysis of the parasite. A method is described by which large quantities of infected blood can be grownin vitrofrom the ring to the trophozoite stage thus allowing direct biochemical analysis of parasites grownin vitro. The results of direct biochemical analysis indicated that parasites grownin vitrohave similar DNA and protein contents to those grownin vitrobut that RNA contents are much lessin vitro. Quantitative histochemical studies also indicated a deficiency in RNA in parasites grownin vitro. It is concluded from the evidence of three distinct methods that RNA synthesis is defective during the first asexual cyclein vitro. In the second cycle all three macromolecular biosyntheses studied are reduced when compared to the first so that the actual rate of RNA synthesis is further reduced when compared to thatin vitro. It is suggested that the successive decrease in RNA synthesis parallels the reduction in multiplication obtained on subculture of the parasite.
A rapid technique for the concentration and collection of Helminth eggs from large quantities of faeces
Authors: Beer R. J. S.
Published: June 2009

A simple semi-mechanical sieving apparatus is described which rapidly concentrates helminth eggs from relatively large volumes of faeces. Tests showed the percentage recoveries of N. battus eggs after sieving 500, 750 and 1000 ml of diluted ovine faeces were 94·1, 88·1 and 84·8 respectively; for T. suis, Oesophagostomum spp. and H. rubidus eggs from 1000 ml. of porcine faeces, the percentage recovery was 94·8 for T. suis and 94·7 for the latter two worms. T. trichuira eggs have also been separated from human faeces using this apparatus.
Filophryxus dorsalis gen.nov., sp.nov., an unusual bopyrid parasite from eastern Australia
Authors: Bruce A. J.
Published: June 2009

An unusual new species of bopyrid parasite is described: unlike other bopyrids, the new species is attached on the dorsal surface of the abdomen of its host, a pontoniinid shrimp Periclimenes hertwigi Balss. A new genus has been erected for the parasite, Filophryxus dorsalis. It is distinguished from other genera by the presence of pereiopods I and II on the longer side of the body and pereiopods I, IV-VI on the shorter side, by three pairs of uniramous pleopods and no uropods on the abdomen. The specimen was collected off the Coast of Queensland, Australia, at a depth of 275 m.
The ecology of the free-living stages of Ostertagia circumcincta
Authors: Gibson T. E. , Everett G.
Published: June 2009

The development and survival of the eggs and larvae of O. circumcincta was studied by spreading the daily faecal output of a sheep over a 2 m square grass plot for 1 week. Observations were carried out for 3 years on material spread at 4-weekly intervals and broadly similar results were obtained in each year. Development time was long in eggs placed outside in January, February, March, November and December. Yields of larvae were small and all were dead within 5 months. During the rest of the year development time was about 2 weeks, yields of larvae were high and larvae survived until July or August of the following year. The significance of these findings in devising systems of grazing management to control parasitic gastroenteritis is discussed.
Studies on the immunity of sheep to Oesophagostomum columbianum: effects of different and successive doses of larvae on worm burdens, worm growth and fecundity
Authors: Dobson Colin
Published: June 2009

The effects of different and repeated doses of Oesophagostomum columbianum larvae on the survival of the adult parasite, its length and the fecundity of the female worm in sheep were studied. Adult worm burdens were dependent on the numbers of larvae administered when sheep were infected once, but not when they were infected twice. It was concluded that these effects were caused by non-specific elimination of worms following a single infection, related to competition for space among larvae and to inflammatory reactions stimulated by them in the gut mucosa which increased with the numbers of larvae given. When sheep were infected once with large numbers of larvae or when they were infected twice the surviving adult population was also influenced by the adaptive immune responses of the host. Parasites recovered from sheep given a single infection of 5000 larvae were stunted compared with worms from sheep given fewer larvae. After a second infection all the worms were stunted and the females produced fewer eggs than did female worms following a single infection; but the numbers of larvae administered did not influence these effects. Egg production was also delayed after a second infection. The reduced fecundity of female worms in the immune host was not related to stunting of the worms, because stunted female worms from sheep infected once with 5000 larvae produced as many eggs as females from sheep infected once with smaller numbers of larvae. It is suggested that the different manifestations of protective immunity in sheep were elicited when threshold levels of infection were exceeded. These levels were represented by between 2000 and 5000 larvae in first, and fewer than 500 larvae in second infections.
Inherent movement patterns of larval nematodes, with a stochastic model to simulate movement of infective hookworm larvae
Authors: Croll Neil A. , Blair Andrew
Published: June 2009

Ancylostoma tubaeforme infective larvae have been tracked in agar and the dominant features of their tracks subjected to a numerical analysis. Very few of the features are uniformly random, most follow a well described normally random frequncy distribution. The mean size of an ‘are’ was 3·61 mm in radius and subtended an angle of 123° at the centre. The length of track per unit time declined with larval age and reversals were the main features to disrupt the pattern of tracks.
The effect of incubationin vitroon the susceptibility of monkey erythrocytes to invasion byPlasmodium knowlesi
Authors: Trigg P. I. , Shakespeare P. G.
Published: June 2009

Rhesus monkey erythrocytes when incubatedin vitrounder similar conditions to those used for the cultivation ofPlasmodium knowlesi-infected erythrocytesin vitro, exhibit an increase both in their osmotic fragility and in the activity of their acetylthiocholinesterase. No effect was observed on the catabolism of glucose through the glycolytic pathway or through the primary dehydrogenases of the pentose phosphate pathway. The ATP content of normal monkey erythrocytes was also unchanged during incubationin vitro. These observations indicate that incubation of erythrocytesin vitroprimarily causes membrane changes. Infection of normal erythrocytes byP. knowlesiwas reduced markedly by preincubation in vitro at 37 °C for 24 and 48 h. These results suggest that the maintenance of integrity of the surface of the eythrocytein vitrois a necessary prerequisite for an efficient culture system for the malaria parasite.
Studies on the hatchability of Schistosoma mansoni eggs from a naturally infected human community on St Lucia, West Indies
Authors: Upatham E. S. , Sturrock R. F. , Cook J. A.
Published: June 2009

A relatively simple, standardized hatching test was devised, tested and used to estimate the Schistosoma mansoni hatching rate for 88 St Lucian subjects selected by age, sex and intensity of infection.

The hatching rate was dependent on the intensity of infection and rose proportionately with it. The rate also decreased with increasing age of the subject. Sex alone had no direct effect but there was a suggestion of an interaction between sex and age.

These results suggest that several hatching tests are necessary, before and after treatment in schistosomicidal drug trials, to permit valid conclusions to be drawn. The hatching data are used in conjunction with survey results to calculate the contamination potential of different age groups in a population. School children (5–14 years old) are about twice as important as young adults (15–29 years old) who, nevertheless, contribute over a quarter of the total contamination potential. However, whereas school children are fairly accessible for mass chemotherapy control programmes, young adults often are not and, furthermore, involve problems associated with the treatment of women of child-bearing age.
Laboratory studies with some older anticoccidials
Authors: Ryley J. F. , Wilson R. G.
Published: June 2009

Features of the anticoccidial activity of nicarbazin, amprolium, zoalene, sulphadimidine, diaveridine, Darvisul, spiramycin, chloramphenicol and Oxytetracycline have been re-investigated both in vivo and in cell culture using Eimeria tenella. Of the drugs studied, only spiramycin was appreciably coccidiocidal, although nicarbazin and amprolium showed possibly slower coccidiocidal activity. In order to show activity against a particular stage in the life-cycle, higher concentrations of drug than those usually recommended for field usage had in most cases to be used. Under these conditions, parasites were usually inhibited as multinucleate 1st generation schizonts. With delayed medication, effects against 2nd generation parasites were in most cases found, and in many cases, although the parasites never matured to give viable merozoites, the large degenerating forms produced were able to cause extensive tissue destruction and haemorrhage. Methodology in this type of study is discussed in relation to more active and more recent anticoccidials, and some further experiments with robenidine reported.
The effect of moisture supply upon the development and hatching of the eggs ofNematodirus battus
Authors: Parkin J. T.
Published: June 2009

Experiments were carried out to investigate the effect of variations in humidity and osmotic pressure upon the development and hatching of the eggs ofNematodirus battus. It was found that no development or hatching took place unless there was free water available, though humidity effects could enhance the subsequent response of the eggs in water. Larvae were found to be very resistant to prolonged exposure to low humidity. The concentration of the hatching medium showed little effect upon development of eggs, though the rate of larval emergence was reduced as the concentration of the culture medium increased. The relevance of this information is discussed in the context of other requirements of the egg stages during their hatching phase and how this may affect the behaviour of this nematode under field conditions.
Dynamic determinants of the route of larval Strongyloides ratti in lactating rats and the control of experimental error in quantitative studies of milk transmission of skin-penetrating roundworms
Authors: Wilson P. A. G. , Gentle Maureen , Scott D. S.
Published: June 2009

Subcutaneous injection of nursing mothers from day 16 to day 20 post partum with infective larvae of Strongyloides ratti or Nippostrongylus brasiliensis does not result in the development of worms in the litters if 1 h is allowed between injection and resumed nursing, and suckling is terminated 24 h later. Thus the low numbers of N. brasiliensis (1% of the dose) which develop in litters after 24 h, 4 day or 5 days suckling when mothers are injected and returned to their young immediately, represent skin invasion and not milk-borne infection.

Taking precautions consistent with the foregoing, S. ratti equivalent to 28%, 45%, 45% and 48% of the dose were shown to be transmitted in the milk to suckling rats of 4 mothers injected with 4000 L 3 on day 18 post partum and 72 h before weaning. One mother of the same batch failed to transmit worms (1% of the dose in the litter) and the take in all 5 mothers was insignificant (max. = 3% of the dose versus an average of 21% in controls).

Large numbers of S. ratti were subsequently found in the intestines of mothers whose litters were weaned immediately after (21%) or 6 h after (16%) injection, whereas very few (less than 1%) developed in mothers deprived of their offspring 24 h after injection. Dynamic, rather than static, determinants of larval routes inside the host present the only logical basis for an explanation of these facts.
The use of vitamin K deficient diets in the screening and evaluation of anticoccidial drugs
Authors: Ryley John F. , Hardman Linda
Published: June 2009

Vitamin K (as menaphthone sodium bisulphite) added to a deficient diet reduced mortality due to Eimeria tenella or E. necatrix, had a slight effect on haematocrit, but had no obvious effect on weight gain or faecal blood; 0·1 ppm gave a maximal response. The effect of vitamin K on mortality was not absolute; the magnitude of the effect depended on the size of the challenge dose of oocysts. Likewise, the response of an infection to anticoccidial drugs, particularly monensin, depended on the severity of challenge. The effect of adding vitamin K in the presence of drug was to effectively reduce the coccidial challenge; no other interaction of vitamin K and drug has been found. No effects with vitamin K deficiency or supplementation were seen in cases of infections with E. acervulina, E. brunetti or E. maxima. The use of a deficient diet for experimental work is therefore quite justified – particularly as it results in a 4-fold saving of oocysts for inoculation purposes in the case of the haemorrhagic species.
Trans-tegumental absorption of L-alanine and L-leucine by a monogenean, Diclidophora merlangi
Authors: Halton D. W.
Published: June 2009

An in vitro investigation has been made of the relative roles of the gut and tegument in the absorption of the neutral amino acids L-alanine and L-leucine by a marine fish-gill parasite, Diclidophora merlangi. The use of ligatures to preclude oral ingestion of trace-labelled medium has proved inadequate, invariably damaging the tegument, as revealed by stereoscan electron microscopy, and resulting in artifactual levels of absorption. Three alternative procedures have given consistently reliable data on the route of entry of low molecular weight substrates. (1) Ultrastructural examination of worms previously incubated in electron-dense cationic tracers has shown that, in vitro, there is no oral intake of sea water. (2) The suspending of worms in trace-labelled medium with the mouth out of the medium and comparing amino acid uptake with that of worms totally immersed in medium has revealed no statistically significant difference in the absorption levels. (3) Application of section (freeze-dried) auto-radiography to detect diffusible isotope has demonstrated directly transtegumental absorption of a neutral amino acid. It is concluded from these experiments that Diclidophora has a tegumental transport system for absorbing certain neutral amino acids, and whilst, clearly, the worm is sanguinivorous and digests blood in a well-developed gut, it may also be capable of supplementing this diet with low molecular weight organic nutrient absorbed directly from sea water via the tegument.
Isolation of chick intestinal cells infected with second-generation schizonts of Eimeria necatrix
Authors: Fernando M. A. , Pasternak J.
Published: June 2009

After infection with Eimeria necatrix, chick intestinal cells undergo a profound increase in size. Herien, we describe methods for isolating and purifying infected cells containing second-generation schizonts at Various times post-infection. Our purification procoedures depended upon three fundamental properties of infected cells: namely (1) large size, (2) resistance to shearing and (3) decreased susceptibility to osmotic shock in hypotonic solutions. The availability of simple techniques for isolating infected whole cells should prove valuable in elucidating various intracellular aspects of infection during schizogony.
The formation and turnover of the membranocalyx on the tegument ofSchistosoma mansoni
Authors: Wilson R. A. , Barnes P. E.
Published: June 2009

The multilaminate vesicles present in the tegument cytoplasm appear to fuse with side channels projecting out into the cytoplasm from the base of the surface pits. Their lamellate contents then unroll and spread out to form a trilaminate membranocalyx lining the pits and covering the tegument surface. The plant lectin concanavalin A appears to stabilize the process of vesicle fusion leading to an aggregation of multilaminate vesicles trapped in the lumen of the surface pits. The membranocalyx can be labelled with cationized ferritin. Chase incubations in normal medium indicate that by 4 h most of the label and the membranocalyx to which it is bound have been lost to the medium. This suggests that under the conditions of these experiments the membranocalyx has a half-life of 2–3 h.
A reassessment of the variations in the water content of the larvae of Nematodirus battus during the hatching process
Authors: Perry R. N.
Published: June 2009

Parkin (1975) considered that the water content of the unhatched 3rd-stage larva of Nematodirus battus increased as it approached hatching, and then fell immediately after the larva escaped from the egg-shell, to the very low value for estimated water content for hydrated individuals of 43·7%. A repetition of this work suggests that these results are in error. Prior to hatching, the water content of larvae remained constant; after hatching there was a marked increase in water content to an estimated value for fully hydrated individuals of 74·5%, a value more in keeping with other findings.
Haemoflagellates: commercially available liquid media for rapid cultivation
Authors: Hendricks L. D. , Wood D. E. , Hajduk M. E.
Published: June 2009

The successful cultivation of a variety of haemoflagellates in three different liquid media is reported. These media include medium 199, Grace's insect tissue-culture medium and Schneider's drosophila medium, each in combination with 30% (v/v) foetal calf serum. These media were used to cultivate Old and New World species of visceral and cutaneous human Leishmania, as well as Leishmania species isolated from sandflies, rodents, and reptiles. Four strains of Trypanosoma cruzi, an isolate of T. rangeli and an isolate of T. lewisi have also been cultivated in these media. One or more of these media have been used to cultivate 121 strains of haemoflagellates, including at least 14 different species (11 Leishmania and 3 Trypanosoma) and many geographic isolates or strains. The Leishmania include L. braziliensis, L. peruviana, L. mexicana, L. tropica, L. donovani, L. chagasi, L. enriettii, L. hertigi, L. hoogstraali, L. adleri, and L. agamae. Using the Schneider's based medium, we have obtained primary isolates of both cutaneous and visceral Leishmania of man and of experimentally infected laboratory rodents and canines. Freeze-dried preparations of the Schneider's based medium that were reconstituted with distilled water after 24 months of storage at ambient temperature have proven to be suitable cultivation media. This feature makes the media valuable field tools.

The various species of human Leishmania cultivated in these media have in our experience demonstrated no differences in growth rate, viability after liquid nitrogen preservation, or infectivity for laboratory animals and tissue-culture cells compared with promastigotes derived from blood-agar cultivation.
Variations in the ultrastructure of the daughter sporocyst ofMicrophallus pygmaeus(Levinsen, 1881) (Digenea: Microphallidae) in chemically defined media
Authors: Popiel Irene , James B. L.
Published: June 2009

Changes in the ultrastructure of the daughter sporocyst and contained metacercariae ofMicrophallus pygmaeusduring culture in artificial seawater and modified Medium 199 were examined and compared with variations in oxygen consumption. The very early commencement and rapid progression of autolysis in the sporocyst body wall as compared with little or no change in most metacercariae in both media, together with the elevated oxygen consumption in the nutrient medium, suggests that most of the oxygen is consumed by the contained metacercariae. The almost simultaneous onset of body wall degeneration in both media suggests that the nutrient medium is not suitable for the maintenance of healthy daughter sporocysts.
The effect of human immune IgG on the in vitro development of Plasmodium falciparum
Authors: Mitchell G. H. , Butcher G. A. , Voller A. , Cohen S.
Published: June 2009

Plasmodium falciparum parasites infecting Aotus trivirgatus erythrocytes were cultured in media (Harvard and TC199) augmented with human, foetal calf, or other sera. Conditions were established which supported growth of parasites and allowed cyclical multiplication when fresh erythrocytes (from Aotus or Homo) were added in sub-culture (mean multiplication rate: x 3). Immunoglobulin G pools, prepared from plasma collected in endemic malarious areas in Africa and from unexposed Britons, were tested for effects on the in vitro growth (measured by incorporation of tritiated leucine) and multiplication of parasites. Whilst non-immune IgG was without effect, IgG from both East and West Africa inhibited the multiplication of East African (Uganda-Palo Alto strain) parasites.