bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbohydrate stores in chickens infected withEimeria tenella
Authors: Freeman B. M.
Published: June 2009

Changes in plasma glucose and lactate and glycogen stores of cardiac and voluntary muscle have been determined during the course of an infection byEimeria tenella.

No hyperglycaemia resulted nor was there any significant change in the stores of hepatic glycogen during the period of observation.

There was a significant reduction in the plasma lactate concentration on the 1st and 2nd days after infection.

There was a transient increase in the stores of cardiac glycogen on the 5th day after infection.

Glycogen stores of voluntary muscle were significantly reduced on the 5th and 6th days after infection. It is thought that this depletion resulted from a reduction in muscular activity rather than from an impairment of glycogenesis.
The effect of temperature on the development of Moniliformis dubius (Acanthocephala) in the intermediate host, Periplaneta americana
Authors: Lackie J. M.
Published: June 2009

The effect of ambient temperature on the ability of Moniliformis dubius to become established in the intermediate host Periplaneta americana, and the effect of temperature on the rate of development of the parasite, has been investigated. Development is postponed at temperatures below 20 °C and infection does not normally occur at 37 °C, the parasites possibly being unable to avoid the defence mechanisms of the host. Both temperatures are tolerated by the host. A marked temperature dependence of rate of development is observed.
The effect of immunosuppressants on the development of Hymenolepis diminuta in mice
Authors: Hopkins C.Adrian , Subramanian G. , Stallard Helen
Published: June 2009

Cortisone, methotrexate and anti-lymphocyte serum were all found to suppress the rejection by SPF CFLP male mice of H. diminuta, which normally occurs between days 9 and 12. Worms continued to grow in mice given immunosuppressants and matured on days 16–18 as they would in a rat, by which time they stretched from the stomach to, and sometimes into, the caecum. Worms in mice given methotrexate ceased to grow after day 16, but this was believed to be due to the deterioration of the host's intestine wall; in mice receiving cortisone growth was faster than normal and worms continued to increase in size until the end of the experiments on days 20–24. The mouse/H. diminuta system is discussed, emphasizing that, as far as is known, H. diminuta (which has no hooks) has no close contact with the tissues and that this is a case of a mammal responding against an organism living freely in the lumen.
Maintenance ofDracunculus medinensis(L.) in the laboratory and observations on experimental infections
Authors: Muller Ralph
Published: June 2009

The ability of various mammals to transmitDracunculus medinensishas been investigated. The most suitable definitive host for laboratory transmission was the rhesus monkey (Macaca mulatta) and, in 11 out of 14 of these animals female worms emerged 321 to 371 days after first infection. The parasite has now been maintained in monkeys for four laboratory cycles. Five of 11 dogs and 17 of 30 cats had developing parasites in their tissues when autopsied, but no worms emerged from two dogs left for over a year and only a single worm from one of nine cats. Monkeys showed a seemingly haphazard pattern of susceptibility to infection and reinfection, although none of the 17 animals exposed was completely refractory.Cyclops vernalis americanus(Marsh) was an easily maintained and efficient intermediate host; a 90% infection rate with an average of two infective larvae perCyclopswas obtained.

This work was supported by a grant from the Tropical Medicine Research Board through the Ministry of Overseas Development. Thanks are due to Mrs Vivian Duckett for technical assistance.
Schistosoma mansoni: ability of Con A to protectin vitromechanically transformed schistosomula against the lethal effect of immune serum plus complement
Authors: van Pijkeren Thea A. , Tavares C. A. P. , Gazzinelli G.
Published: June 2009

Concanavalin A added to a defined culture medium renders schistosomula more resistant to the lethal effect of antibody plus complement. The Con A dose-dependent acquisition of protection reached a plateau at a concentration of 4 μg Con A/ml. α-Methylmannoside was not able to reverse the Con A-induced protection but excess methylmannoside, added to the incubation medium together with Con A partially prevented the effect of the lectin. Binding of anti-parasite antibody to the schistosomula surface did not change after pre-incubation with Con A. In the presence of puromycin (100 μg/ml) Con A is still able to confer protection. Incorporation of labelled amino acid into the tegumental proteins was not affected by Con A. Furthermore, a progressive reduction of protection was observed as the time of culture preceding Con A addition increased.
Effects on abomasal function ofOstertagia circumcinctainfections in sheep
Authors: McLeay L. M. , Anderson N. , Bingley J. B. , Titchen D. A.
Published: June 2009

Sheep in which abomasal fundic pouches had been made were infected withOstertagia circumcincta(150000 larvae in one sheep, 100000 in three sheep). Subsequently studies were made on pouch secretion, food intake, plasma pepsinogens and abomasal pouch secretory responses when the sheep first ate. A functional abomasal lesion was apparent within 4 days of infection judged by the changes in plasma pepsinogen levels and the sodium concentrations of abomasal contents. Whereas the secretory activity of the abomasal fundic pouches (never exposed to parasites) was maintained or increased, the pH and sodium concentration of contents taken from the infected part of the abomasum were indicative of either a failure to secrete or of a permeability reabsorptive lesion. Ultrastructural studies demonstrated that parietal cells of the pouches had the appearance of cells subjected to strong secretory stimuli, but those of infected abomasa were similar to cells of gastric mucosa subjected to agents suppressing secretion. Factors which might operate, on the one hand, to stimulate secretion from separated fundic abomasal pouches, and on the other to inhibit or modify the secretory activity of the fundic mucosa of the infected abomasa, are discussed.
Trypanosome infection rates inGlossina swynnertoniandG. pallidipesin Ikoma, Musoma District, Tanzania
Authors: Moloo S. K. , Steiger R. F. , Brun R.
Published: June 2009

In a survey of animal trypanosomiasis in Musoma District, carried out in October and November 1970, 6344G. swynnertoniwere collected from six different localities of the Ikoma-Serengeti area and 623G. pallidipesfrom Ikoma. These were dissected and examined for trypanosome infections. The mean infection rates ofvivax-type inG. swynnertoniandG. pallidipeswere 12.6% and 7.5%, respectively. Thecongolensegroup infection rates were 2.0% inG. swynnertoniand 1.8% inG. pallidipes. No salivary gland infection was encountered. The incidence of vivax- and congolense-type infections in general increased with age of both the tsetse species, suggesting that the latter can become infected with these trypanosome types at all ages. The infection rate among female tsetse was higher than among males in the six wing-fray categories. This was due to the slower rate of fraying of the wings with age of the former, so that at each wing-fray category the females were generally older than the males.Vivax-type greatly exceededcongolense-type infection rate in bothG. swynnertoniandG. pallidipes. It is suggested that this probably reflects the known greater infectivity of the former group of trypanosomes toGlossina. It is concluded that in Ikoma, where game functions as the reservoir of animal trypanosomiasis and where infected tsetse are abundant, the domestic animals are exposed to a continuous trypanosome challenge.
The effect of oxyclozanide on Hymenolepis microstoma and H. diminuta
Authors: Hopkins C. A. , Grant P. M. , Stallard Helen
Published: June 2009

The effect of oxyclozanide (2,2′-dihydroxy-3,3′,5,5′,6-pentachlorobenzanilide) on Hymenolepis microstoma in the bile duct of mice, and H. diminuta in the small intestine of mice and rats was measured.
Oxyclozanide at doses as low as 4mg/kg removed 13-day-old H. diminuta and caused no obvious harmful effect to the rat host up to the maximum level (256 mg/kg) tested. Worms were displaced and degenerating within 1 h. Results in mice were more difficult to assess because of the immune response, but similar total amounts of oxyclozanide caused destrobilation and loss of 7-day-old H. diminuta.
Oxyclozanide was less effective against 21-day-old H. microstoma attached in the bile duct. Approximately half the strobila was lost following dosing at 5 mg/kg and progressively greater amounts as the dose level was increased. At 50 mg/kg worm loss commenced but even at 150 mg/kg 25 % of worms survived. The time taken to regrow to the original adult size varied but was complete within 7–9 days at levels up to 25 mg/kg. Double dosing at 5-day intervals did not enhance the effect of a single dose. The apparent existence of a sensitivity gradient down the strobila in H. microstoma is discussed.
The development of Eimeria acervulina in the caeca of young fowls
Authors: Joyner L. P. , Norton C. C.
Published: June 2009

A laboratory strain of Eimeria acervulina was found to develop in the caeca when large numbers of excysted sporozoites were injected into that organ. Both schizonts and gametocytes were formed, but parasitization of the caeca was never heavy and did not increase with serial passage. The infection was not increased by the simultaneous injection of betamethasone.
The effect of early cyclophosphamide treatment on the subsequent immunity of chickens to coccidial infections
Authors: Joyner L. P. , Norton C. C.
Published: June 2009

Chicks were treated with cyclophosphamide during the first 3 days of life in order to effect chemical bursectomy. They subsequently showed a reduced capacity for the production of serum agglutinins toBrucella abortusand immunolysins to sporozoites ofEimeria tenella. They also developed a reduced immunity toE. tenellaorE. maximacompared with that produced in normal birds. The evidence provided by these experiments for the role of circulating antibodies in immunity to coccidiosis is discussed.
The ascaridoid nematodes of rodents with a redescription ofPorrocaecum ratti
Authors: Sprent J. F. A.
Published: June 2009

Two ascaridoid nematodes occurring in rodents in South-East Asia, namelyPorrocaecum rattiandToxocara mackerrasae, were compared; the former was redescribed. These and other ascaridoid species occurring in rodents were classified and it was suggested that relative to the other mammalian orders, the rodents are well endowed with ascaridoids. There is, as yet, insufficient evidence for conjecture as to whether species occurring in rodents represent primitive forms from which the species occurring in predatory animals may have been evolved through host—succession—extension, or whether they have been secondarily derived through loss of a predatory definitive host through host—succession—reduction.
Tissue fluid in rabbits infected withTrypanosoma(Trypanozoon)brucei
Authors: Goodwin L. G. , Guy M. W.
Published: June 2009

Perforated plastic cylinders (hair curlers) were implanted subcutaneously in rabbits for the collection of tissue fluid. Using this technique, a study was made of the chemical constituents of tissue fluid and serum in rabbits infected withTrypanosoma (Trypanozoon) brucei, as compared with uninfected, control animals. Changes were caused by the infection in the concentrations of proteins, electrolytes, urea, creatinine, cholesterol and pyruvate, and in the activities of the enzymes aspartate transaminase, creatine phosphokinase and alkaline phosphatase. Antitrypanosomal antibody, detectable by the indirect fluorescent antibody technique, was shown to penetrate the tissue fluid and to reach a titre of about one-fifth of that in the serum. Renal failure, probably resulting from allergic reactions, was shown to be a contributory cause of death in rabbits infected withT. (T.)brucei.
Studies on the host specificity of the eyefluke, Diplostomum spathaceum, in brown and rainbow trout
Authors: Betterton Christine
Published: June 2009

Trout collected from the Hanningfield Trout Farm in Essex, England, were found to be infected with Diplostomum spathaceum. Yearling rainbow trout were blinded with heavy infections of eyefluke, whereas brown trout of the same age carried one-tenth the number of flukes and were clear eyed. Both species were reared under identical conditions, in parallel rearing channels which received water from a common source. Samples showed that young fish exhibited a similar differential in their infestations, and that rainbow trout did not appear to be age-resistant. Laboratory infections produced by exposure of fish to suspensions of cercariae and injection of cercariae into the body cavity reflected the field results, indicating that ecological factors were not involved. Recovery of cercariae from host tissues, and histological observations of similar numbers entering both hosts, indicated that cercariae were able to survive penetration. Excised eye preparations were equally susceptible to infection. Two cm fry of both species were shown to be highly susceptible. Migration in brown trout took 3 h longer than in rainbow trout of the same size, many cercariae being found in the heart during this time. Two mechanisms of insusceptibility were suggested: (1) a greater impenetrability of brown trout tissues; (2) a disorientation of migrating cercariae in brown trout.
Delayed rejection of singleHymenolepis diminutain primary infections of young mice
Authors: Befus A. D. , Featherston D. W.
Published: June 2009

In CFLP male tapeworm-free mice, from 2 to 7 weeks old at infection, at least 80% of singleHymenolepis diminutaestablish and grow but then are rejected; day of rejection defined as the first day when ≦ 50% of the worms were recovered. Young mice, 2 to 4 weeks old, usually reject their worms during days 16–20 while older mice, 5 to 7 weeks old, reject them during days 12–14. Biomass (total dry weight of all worms recovered on a given day from a group of mice) varied markedly with host age and was consistently greatest in 4-week-old mice. The position of the worm in the intestine did not vary with host age. The quality of mice (categorized by the Medical Research Council Laboratory Animals Centre) did not appear to affect the course of a primary, singleH. diminutainfection although, undoubtedly, the mice had varied immunological histories. Variations in time of rejection and biomass of worms recovered are accounted for by both immunological and physiological mechanisms.
The organization of the ookinete and observations on nuclear division in oocysts of Plasmodium berghei
Authors: Canning Elizabeth U. , Sinden R. E.
Published: June 2009

Ultramicroscopic features of the ookinete/oocyst transformation in Plasmodium berghei are described. The apical complex of organelles and some pellicular components, believed to be responsible respectively for cell penetration and body form were resorbed into the cytoplasm shortly after the ookinete came to rest under the basal lamina of the midgut wall. Within a single digitate nucleus, spindles at different phases of division were observed with kinetochores in early and late anaphase position. From the number of kinetochores the chromosome complement was estimated at 5–10.
Morphological descriptions of the egg and larval stages ofTrichuris suisSchrank, 1788
Authors: Beer R. J. S.
Published: June 2009

The egg and larval stages of Trichuris suis can be briefly characterized as follows: The egg: barrel shaped, possesses a thick shell consisting of three thick outer layers and an inner thin vitelline membrane, is operculate at each end and is unsegmented and unfertilized when freshly deposited. L. 1 within the egg: presence of an oral spear, a poorly denned oesophagus and an intestinal tract consisting of undifferentiated granulated material. L. 1 within the host: initial differentiation of an oesophagus, cell body, intestine and rectum. L. 2: further differentiation of the body organs and the appearance of the rudiments of the reproductive system. L. 3: initial development of reproductive system and development of a cloaca in the male thus distinguishing the sexes. L. 4: differentiation of reproductive system into vagina, uterus, oviduct and ovary in the female, and testis, vas deferens, ejaculatory duct, spicule and spicular muscle, sheath and tube in the male. L. 5 or adult stage: completed development of the sexual organs including formation of the vulval orifice and eggs in the female and seminal vesicle in the male.
Studies on host resistance to secondary infections of Raillietina cesticillus Molin, 1858 in the fowl
Authors: Gray J. S.
Published: June 2009

Worms of secondary infections of Raillietina cesticillus established in 10-week-old birds but failed to grow mature strobilae. This was taken as an indication of resistance to the cestode. The resistance was inhibited by the immunosuppressant and anti-inflammatory drug dexamethasone, which prevented the local inflammation around attached scolices characteristic of secondary infections of R. cesticillus. Mast cell hyperactivity and eosinophil infiltration in intestinal tissues and immunofluorescent antibodies in sera of infected birds were also demonstrated.
Scolices without strobilae from refractory hosts with both primary and secondary infections regrew their strobilae when transplanted into susceptible hosts.
Malaria, quinine and red cell lysis
Authors: Laser Hans , Kemp Patrick , Miller Nigel , Lander David , Klein Roger
Published: June 2009

An hypothesis is presented to explain the red cell lysis which accompanies an acute malarial infection, as well as the mode of action of certain schizonticidal drugs in the quinoline and acridine series. Quinine and a number of other antimalarial drugs have been found to counteract the inhibition by protein of fatty acid-induced lysis, when tested in anin vitrosystem. It is suggested that these schizonticides exert their chemotherapeutic effect by inducing the premature lysis of the parasitized red cell, as a result of relieving the inhibition by protein of haemolysis.
The release of antigens byPlasmodium falciparum
Authors: Wilson R. J. M. , Bartholomew R. K.
Published: June 2009

Antigens were releasedin vitrofrom human red cells infected withPlasmodium falciparumonly when parasites reached a late stage of schizogony (probably at rupture of infected red cells during reinvasion). Immune complexes formed if antibody was present. Serum from immuneAotusmonkeys opsonized parasite debris from artificially disrupted infectedAotusred cells.
Parasitic helminths of the American avocet Recurvirostra americana: four new species of the families Hymenolepididae and Acoleidae (Cestoda: Cyclophyllidae)
Authors: Ahern W. B. , Schmidt G. D.
Published: June 2009

Records are presented of 11 species of parasitic helminths recovered from 37 American avocets. Birds were collected in Kansas and Colorado from April 1973 to August 1974. Parasites found included 3 trematodes, 2 nematodes, 1 acanthocephalan and 5 cestodes, 4 of which are new species. Hymenolepis cervotestis sp.n. (Hymenolepididae) is described from the small intestine of 7 avocets. It exhibits extreme protandry with the testes appearing before external segmentation is evident. Sobolevicanthus coloradensis sp.n. (Hymenolepididae) is described from the small intestine of 4 avocets. This species is found to have its scolex embedded in the intest-tinal mucosa of its host. Diorchis recurvirostrae sp.n. (Hymenolepididae) is described from specimens recovered from the small intestine of 5 avocets. Diplophallus coili sp.n. (Acoleidae) is described from the small intestine of all 37 avocets. The family Diploposthidae is suppressed and the family Acoleidae is emended to include the 4 genera previously placed in Diploposthidae. A key to the genera of Acoleidae is presented.
Haemoproteid parasites of Passer spp
Authors: Peirce M. A.
Published: June 2009

The taxonomic status of the haemoproteid parasites hitherto described from the avian genus Passer is reviewed. It is concluded that 1 species only is valid Haemoproteus passeris Kruse (1890), all other species being designated as synonyms. From material obtained from Passer domesticus a re-description is given of H. passeris which has been shown to exhibit a wide range of morphological forms. The reasons for this are discussed. Schizogonic stages are described for the first time for this species, and evidence is presented which suggests that H. passeris does not belong to the sub-genus Parahaemoproteus. Schizogonic stages previously considered to be from Passer spp. probably originated from birds of another genus and family. H. passeris appears to be restricted to the avian genus Passer in which it has a world-wide distribution.
Possible immunological damage to the tegument ofHymenolepis diminutain mice and rats
Authors: Befus A. D. , Threadgold L. T.
Published: June 2009

Opaque or darkened areas (DA) of variable size and position occur onHymenolepis diminutain mice and rats. In mice DA normally first appear in the neck region of the worm but subsequently they appear elsewhere and increase in number until destrobilation or worm expulsion. The posterior of destrobilated worms is often darkened. In the more immunogenic infections with six cysticercoids there are more DA per worm than in infections with one cysticercoid. DA are areas of the tegument with a homogeneous increase in electron density; abnormal mitochondria; reduced granular endoplasmic reticulum, Golgi complexes and discoidal secretory bodies; and accumulation of lipid droplets. DA disappear from worms maintained for up to 4 h in Hanks' balanced salt solution and can be induced by mechanical damage to the worms.

As the numbers of DA increase with the duration and intensity of infection and have similarities with types of cell injury, they are probably sites of worm pathology induced by host immunity.
Plasmodium falciparum gametocytes: their longevity and infectivity
Authors: Smalley M. E. , Sinden R. E.
Published: June 2009

The longevity and infectivity of isolated populations of Plasmodium falciparum gametocytes were studied. Following chloroquine treatment gametocyte numbers fell with a constant rate of loss over a period of 16–24days; the populations had a half-life of 2·4 days. The sex ratio stayed constant throughout at 4 female:1 male. The ability of the microgametocytes to exflagellate and the infectivity of the population to mosquitoes persisted for 3 weeks. Antibodies to the gametocytes were detected but not in every patient studied. It was concluded that the gametocytes of P. falciparum are both long-lived and show persistent infectivity to mosquitoes. They can stimulatae antibody production but the immune response appears to play no part in their elimination, which probably takes place in the spleen as a part of the normal process of removing old, damaged and malformed red cells.
Cryptocotyle lingua (Creplin) (Digenea: Heterophyidae): observations on the morphology of the redia, with special reference to the birth papilla and release of cercariae
Authors: Irwin S. W. B. , Threadgold L. T. , Howard Nicola M.
Published: June 2009

Rediae of Cryptocotyle lingua were studied using transmission and stereoscan electron microscopy. The mouth is surrounded by numerous ciliated sensory structures. Posteriorally, the body wall is concentrically folded and its surface area is greatly increased by the closely ridged configuration of the outer membrane of the tegument. Attached to the surface, especially at the anterior end, are numerous, small spherical vesicles. At the posterior end there is a retractable papilliform process. The appearance of the surface of the birth papilla is variable. The birth pore is lined by an epithelium which is specialized to withstand extreme distortion. A single cilium is frequently visible in the birth pore lumen. The release of each cercaria is preceded by the emission of a tiny drop of fluid from the birth pore. It is suggested that this fluid acts as a lubricant to the passage of the cercaria through the pore.
Observations on non-pigmented haemosporidia of Brazilian lizards, including a new species ofSaurocytozooninMabuya mabouya(Scincidae)
Authors: Lainson R. , Landau Irène , Shaw J. J.
Published: June 2009

Of 63 specimens of the lizardMabuya mabouya(Scincidae) examined in Pará State, Brazil, 31 showed one or more haemosporidians in the peripheral blood. These includedGarnia(Plasmodium)morula(Telford, 1970), Lainson, Landau & Shaw, 1971;Plasmodium tropiduriandP. diploglossiAragão & Neiva, 1909; aPlasmodiumspecies close toP. diminutivumTelford, 1973a; and a new species ofSaurocytozoonLainson & Shaw, 1969a. Eleven different combinations of these parasites were noted, emphasizing the care needed in avoiding erroneous descriptions based on mixed infections. This is especially so whenG. morulais mixed withP. tropidurior other species with small, rounded gametocytes occupying a polar position in the red blood cells. Of 18 skinks infected withG. morula, 10 had pure infections, as judged by repeated examinations over long periods. The morphology of the Brazilian parasite is very similar to that described forG. morulafrom Panama (Telford, 1970): no malarial pigment could be demonstrated in any stage of the infection, including ookinetes and possible early oocysts which were studied in experimentally infectedCulex pipiens fatigans. Ookinetes and rounded forms, possibly representing uninucleate oocysts, persisted in these insects up to 24 h after the blood-meal, but developed no further.C. p. fatigansis thus unlikely to be a natural vector ofG. morula. Saurocytozoon mabuyisp.nov. is described inM. mabouya: the gametocytes develop in the lymphocytes and monocytes of the circulating blood and reach maximum size in 19–28 days. The parasite can be distinguished from the other known species,S. tupinambiof the teiid lizardTupinambus nigropunctatus, by its smaller gametocytes. Nothing is known of the sporogonic cycle. Differences between the sporogonic stages ofS. tupinambiandLeucocytozoonare listed.
Cercariae of Microphallidae: determination of the generaMicrophallusWard, 1901 andMaritremaNicoll, 1907 according to chaetotaxy
Authors: Richard Josette
Published: June 2009

This study compares papillae distribution in seven microphallid cercariae of the generaMicrophallusandMaritrema. Certain papillae or groups of papillae have generic, supra–generic or specific significance. Microphallidae are characterized by the absence of C I cycle and of dorsal P II and P III, the presence of one C II1and one C II2, of four mediodorsal A I D papillae and of two horizontal papillae on the tail. The number and disposition of the papillae at the front of the body (peribuccal and anterodorsal A I D and St DL) and at the back (P cycles) have a generic significance. The number and disposition of the papillae in the middle of the body (A and M cycles) have a specific significance.
Active entry of bloodstream forms ofTrypanosoma cruziinto macrophages
Authors: Kipnis T. L. , Calich V. L. G. , da Silva W. Dias
Published: June 2009

The uptake of bloodstream forms ofTrypanosoma cruzi, Y and CL stocks, by mouse peritoneal macrophages and their intracellular differentiation and multiplication has been comparedin vitro. After 48 h the number of macrophages showing intracellular amastigote forms was higher when the Y stock was used. The number of parasitized cells increased with the time of contact between parasites and macrophages. Prior treatment of the parasites with anti-T. cruziantibodies and/or complement increased the number of infected macrophages, but did not interfere with their subsequent differentiation within the macrophages. The number of parasitized cells was greater when macrophages were obtained from mice previously treated with lipopolysaccharide, peptone or thioglycollate. Uptake was not appreciably affected when macrophages were pre-treated with trypsin or anti-macrophage serum, or when the parasites and macrophages were incubated in the presence of cytochalasin B. In the same experimental conditions, epimastigotes ofT. cruziwere not able to differentiate into amastigotes. Their uptake was potentiated by previous treatment with specific antibodies and/or complement and was blocked by cytochalasin B. These results confirm that epimastigotes derived fromT. cruzicultures are phagocytosed and suggest that bloodstream forms penetrate actively into macrophages.
Effects of saturated sodium chloride solution on coccidial oocysts
Authors: Ryley Nicholas G. , Ryley John F.
Published: June 2009

Using the ability to sporulate as a measure of viability, the effects of exposure of unsporulated oocysts of 10 species of coccidia of chickens, rabbits and cattle to saturated NaCl solution has been studied. Although appreciable deformation and collapse of the oocyst occurred after 1–2 days contact, the effect was reversible after washing free from salt and incubating. Some reduction in ability to sporulate following several days contact with saturated salt was noted in most species, although no effect was seen with Eimeria stiedai following 7 days exposure, Eimeria tenella was one of the more sensitive species studied. Culture titration experiments in chickens with E. tenella indicated that oocysts which had sporulated following prolonged exposure to salt were in no way inferior in virulence or ability to retain virulence on prolonged storage to oocysts prepared with minimal contact with salt. No evidence was obtained to contra-indicate the use of salt-flotation methods for the separation of oocysts from faeces.
Some blood parasites of the Brazilian lizardsPlica umbraandUranoscodon superciliosa(Iguanidae)
Authors: Lainson R. , Shaw J. J. , Landau I.
Published: June 2009

An examination of 235Plica umbraand 167Uranoscodon superciliosa(Sauria: Iguanidae) from Belém, Pará, Brazil, has revealed a number of hitherto undescribed blood parasites. These includeFallisia audaciosa, F. simplex, Garnia multiformis, Plasmodium vacuolatumandTrypanosoma plicaespp.nov., all inP. umbra, andG. uranoscodonisp.nov. inU. superciliosa. In addition, both species of lizards showed occasionalEperythrozoonand microfilaria infections. Among the haemosporines,F. audaciosais particularly interesting in its restriction to the neutrophils; andG. multiformisfor its early development in erythroblasts of the bone-marrow, and its variable morphology in subsequent stages of the infection in the peripheral blood. Mixed infections of the different haemosporines resulted in 18 combinations of parasites inP. umbra, indicating the importance of examining a large number of these animals when preparing descriptions of the individual organisms.T. plicaeis a large, broad trypanosome, averaging ∼ 57·0 × 16·0 μm. Isolation of the parasite was made from four out of sixP. umbra, after the culture of heart blood in NNN medium: the fact that none of the four positive lizards showed detectable trypanosomes in the peripheral blood suggests a high incidence of occult infections. The incidence among the remaining 229P. umbra, as given by the direct examination of blood-films, was only 10·0%.
Neutralization of individual variable antigen types in metacyclic populations ofTrypanosoma bruceidoes not prevent their subsequent expression in mice
Authors: Barry J. D. , Crowe J. S. , Vickerman K.
Published: June 2009

TheTrypanosoma bruceimetacyclic population in the salivary glands of the tsetse fly displays a characteristic set of variable antigen types (VATs) which represents only a restricted part of the parasite's total VAT repertoire. After introduction into the mammalian host by fly bite, the metacyclics transform into bloodstream forms which retain expression of the metacyclic VATs. Specific antibodies, both polyvalent and monoclonal, have been used to neutralize separately 4 individual VATs from metacyclic populations. Control experiments and visual observation confirmed lysis of each VAT. On injection of the surviving trypanosomes, after washing, into mice each neutralized VAT was nevertheless expressed within a few days. Simultaneous neutralization of 2 metacyclic VATs which usually switch to one another in bloodstream infections did not prevent expression of either on subsequent injection into mice. Expression of neutralized VATs was not influenced by the antigenic composition of the population originally ingested by the tsetse fly. Metacyclic forms and their immediate successors thus appear to switch rapidly to expression of other metacyclic VATs in bloodstream populations.
Oviposition, hatching and the oncomiracidium of Eupolystoma anterorchis (Monogenoidea)
Authors: Tinsley R. C.
Published: June 2009

Eupolystoma anterorchis Tinsley, 1978, infects the urinary bladder of Bufo pardalis at the Cape, South Africa. Reproduction occurs throughout the year but the eggs are not deposited continuously: up to 300 are retained in the long uterus of the parasite and may develop to the point of hatching. The eggs are deposited intermittently en masse. The stimulus for deposition appeared to be osmotic, since worms transferred from the host's bladder into freshwater released their stored eggs. However, in simple experiments where hosts were transferred from dry land to water such egg deposition did not follow and the stimulus requires further investigation. Once discharged from the uterus the oncomiracidia hatch rapidly both in water and in host urine. Those eggs immediately expelled from the bladder at urination release larvae which can infect the same or other host individuals via the cloaca. But when eggs are deposited in the bladder between successive host urinations larvae can emerge and attach themselves directly to the bladder wall. These larvae develop to maturity alongside their parents, and this internal re-infection can give rise to massive levels of infestation. The distributions of the tegumental ciliated cells and sensillae of the oncomiracidium have been determined with silver impregnation. There are 55 ciliated cells whose pattern corresponds with that of Polystoma species except for the orientation of three dorsal cephalic cells. The distributions of their tegumental sensillae show greater divergence and the Eupolystoma larva lacks the hamulus primordia typical of Polystoma.
A scanning electron microscope study of the effect of an ovicidal fungus on the eggs of Ascaris lumbricoides
Authors: Lýsek H.
Published: June 2009

Aspects of the ovicidal activity of the fungus Verticillium chlamydosporium Goddard on the eggs of Ascaris lumbricoides were observed in the laboratory using a scanning electron microscope. The hyphae of the fungus form structures which are considered to be penetration organs. The hyphae also form a network over the surface of the eggs. After penetration of the eggs, the hypha or hyphae ramify and the embryos are destroyed.
Schellackia landauaesp.nov. (Eimeriorina: Lankesterellidae) in the Brazilian lizardPolychrus marmoratus(Iguanidae): experimental transmission byCulex pipiens fatigans
Authors: Lainson R. , Shaw J. J. , Ward R. D.
Published: June 2009

A new haemogregarine,Schellackia landauaesp.nov., is described in the Brazilian lizardPolychrus marmoratus(Linn) from Pará State, north Brazil. Sporozoites are found principally in the red blood cells (84%) in the peripheral blood but also occur in lymphocytes and monocytes. Experimental transmission to three uninfectedP. marmoratuswas achieved after feeding them with laboratory-bredCulex pipiens fatiganswhich had engorged on an infected lizard 14 days previously. The cycle of development in the small intestine ofP. marmoratustakes approximately 30 days: schizogony, gametogony and fertilization of the macrogametocytes is in the epithelial cells of the gut, with zygotes penetrating the lamina propria, where the mature oocysts develop. Living oocysts average 14·3 × 13·3 μm, and are approximately 10·0 μm as seen in histological sections. During the period of intestinal development, the parasite also undergoes asexual multiplication within cells of the spleen and liver by a process which appears to be endodyogeny. The exact time required before the first invasion of the peripheral blood by the sporozoites remains to be ascertained, but is some time within 30–45 days after the lizard ingests the infected mosquitoes. Morphology of the sporozoite in the vertebrate host is variable and depends on the host cell occupied; there may be 1 or 2 refractile bodies. Reduction or fusion of these to a single refractile body in those sporozoites within the gut cells of the infected mosquito suggests that the bodies may represent some form of energy source that is used up during this latent phase in the insect vector. Accumulation of sporozoites takes place in the reticulo-endothelial cells of the viscera, in particular the pigmentladen cells of the liver and lung. Attempts to infect other species of lizards,Tropidurus torquatus(Iguanidae) andAmeiva ameiva(Teiidae) failed.
Accelerated expulsion of adult Trichinella spiralis in mice given lymphoid cells and serum from infected donors
Authors: Wakelin D. , Lloyd M.
Published: June 2009

Immunity to the adult stage of Trichinella spiralis, assessed by an acceleration of worm expulsion, was transferred to recipient mice with mesenteric lymph node cells (MLNC) or serum taken from infected donors. Immunity was transferred most effectively by MLNC taken from donors infected for 8 days, i.e. donors actively responding to infection. Transfer of both MLNC and serum brought about a marked acceleration of worm expulsion in all cases, even where MLNC or serum given separately failed to transfer a significant degree of immunity.
Studies on immunity with three species of avian trypanosomes
Authors: Molyneux David , Gordon Elizabeth
Published: June 2009

The ability of three species of avian trypanosome, Trypanosoma corvi, T. bouffardi and T. everetti, to protect against heterologous and homologous challenge has been studied in susceptible birds. None protects against challenge with either or both of the other two species and mixed infections can be obtained experimentally. With T. bouffardi, both apparently sterile and premune states exist after initial infection and the host is immune to challenge with homologous strains; heterologous strains sometimes break this immunity and produce shorter, lower parasitaemias. T. everetti remains in the circulating blood for long periods at low levels and challenge doses with the homologous strain result in a slightly elevated parasitaemia for a few days. T. corvi produces a degree of immunity after the initial infection which usually results in a reduced second parasitaemic peak of shorter duration when birds are challenged with a homologous strain.
Infections withEimeria maximaandEimeria acervulinain the fowl: effect of previous infection with the heterologous organism on oocyst production
Authors: Rose M. Elaine
Published: June 2009

Judged by oocyst production, infections withEimeria acervulinain birds immunized withE. maximawere consistently higher than in birds which had not been immunized. Oocyst production ofE. maximain birds previously infected withE. acervulinawas greater, in three out of four experiments, than in control chickens, but some of the differences were slight. The findings are discussed but no satisfactory explanation can be offered. In general there was little or no difference between the oocyst production of the individual species when present as single or mixed infections.
Diplostomum spathaceum(Rud. 1819): effects of physical factors on the infection of rainbow trout (Salmo gairdneri) by cercariae
Authors: Stables J. N. , Chappell L. H.
Published: June 2009

The relationship between infection rates of rainbow trout (Salmo gairdneri) byDiplostomum spathaceumand cercarial concentration, water flow rate and temperature were investigated by means of controlled infections within a flume. A linear relationship was obtained between cercarial concentration and mean abundance of metacercariae/fish. A biphasic relationship occurred between flow rate and abundance of metacercariae. Within the confines of the flume, it was possible to control the infection rate of trout withD. spathaceumcercariae by manipulating flow rate, suggesting that it may be a possible method of controlling diplostomiasis on fish farms. No infection occurred in fish infected and maintained below 10°C and the optimum infection temperature was approximately 17·5°C. Infections became established in fish infected at 7·5 and 5°C but maintained at 15°C prior to examination. Trout were infected at 7·5°C for 10–50 min and all attached cercariae were washed off and removed from the flume. Following infection, fish were either maintained at 7·5°C or 15°C prior to examination. Using this method, it was possible to ascertain that it was migration and not penetration which was inhibited at water temperatures below 10°C.
A comparison of the surface and secertions ofTrichinella pseudospiralisandT. spiralis
Authors: Almond N. M. , McLaren Diane J. , Parkhouse R. M. E.
Published: June 2009

Intact, viable adults, infective and newborn larvae ofTrichinella pseudospiraliswere surface labelled with125I by the chloramine T method and labelled proteins were compared with those obtained from equivalent stages ofT. spiralis. Electron-microscope autoradiography determined that labelled proteins were restricted to the cuticle for all stages of both isolates. Comparative polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS–PAGE), using thin gradient gel slabs, of proteins obtained from each stage, demonstrated that the profile of surface-labelled proteins ofT. pseudospiraliswere restricted in number, stage specific, and similar to equivalent proteins ofT. spiralisboth in size and in their organization into aggregates. The stage-specific profiles of surface-labelled proteins derived from newborn larvae were indistinguishable, but differences were noted between adults and infective larvae of the two isolates. These differences in protein structure were confirmed by two dimensional mapping of tryptic peptides. Stage-specific profiles were also obtained when [35S]methionine biosynthetically labelled secretions of the 3 stages ofT. pseudospiraliswere compared by SDS–PAGE. Comparison of the profiles obtained with secretions for respective stages ofT. spiralisagain failed to distinguish newborn larvae, but adults and infective larvae ofT. spiralisandT. pseudospiralisdisplayed a mixture of common and species-specific proteins. These findings are discussed in relation to the different pathology associated with infection with two isolates.
Acetylcholinesterase activity in Nippostrongylus brasiliensis during the course of a primary infection in normal and in protein-deficient rats
Authors: Martin Jean
Published: June 2009

Acetylcholinesterase (AChE) activity was measured in Nippostrongylus brasiliensis recovered during the course of a primary infection in normal and in protein-deficient rats. In well-nourished rats the amount of AChE present in N. brasiliensis increased as the infection progressed, concomitant with the development of the humoral response. In malnourished rats, there was a similar and parallel increase in the amount of AChE synthesized by worms between days 7 and 13 of the infection but as the infection progressed enzyme production decreased so that, by day 26 of the infection, the nematodes contained approximately the same amount of AChE as 8-day-old worms. The possible reasons for this change in enzyme production are discussed.
Evasion of the oxidative microbicidal activity of human monocytes by trypomastigotes ofTrypanosoma dionisii
Authors: Thorne Kareen J. I. , Glauert Audrey M. , Svvennsen Rosamund J. , Thomas H. , Morris Jane , Franks D.
Published: June 2009

Trypomastigotes ofTrypanosoma dionisii, a stercorarian trypanosome from bats, are effectively killed by neutrophils from human peripheral blood but are less sensitive to the cytotoxic action of human monocytes. The mechanism of killing appears to involve peroxidase and hydrogen peroxide. Trypomastigotes are as effective as epimastigotes in inducing the formation of hydrogen peroxide by effector cells. They are, however, less sensitive than epimastigotes to the cytotoxic effect of peroxidase and hydrogen peroxide. They are therefore susceptible to the high concentrations of peroxidase found in the phagosome of the neutrophil, but resist the lower levels encountered in monocytes.
Progess in immunization against parasitic helminths
Authors: Lloyd Sheelagh
Published: June 2009

Helminths are extremely numerous and cosmopolitan parasites of man and domesticated animals and they are responsible for considerable clinical and sub-clinical disease and tremendous economic loss. Thus, immunization against the parasitic helminths of man and animals would be of major health importance and to considerable economic advantage.
Antigenic analysis of sequential erythrocytic stages ofPlasmodium knowlesi
Authors: Deans J. A. , Dennis E. D. , Cohen S.
Published: June 2009

The antigenic composition of sequential erythrocytic stages ofPlasmodium knowlesihas been compared by crossed immuno-electrophoresis using a pool of immune rhesus monkey antiserum. Eleven major parasite antigens have been identified; 9 are stage-independent, and 2 stage-dependent. Differences in the relative amount of the stage-independent antigens have been demonstrated and quantified. The distribution of antigens between parasites and schizont and infected red cell membranes has been examined. Only 6 of the 11 parasite antigens were exhibited by a schizont membrane preparation, all these antigens were also expressed by the intracellular parasite. Antigens exclusive to the schizont membrane were not demonstrated.
Nematodirus battus: structure of the body wall of the adult
Authors: Martin Jean , Lee D. L.
Published: June 2009

Males ofNematodirus battushave a body wall composed of a longitudinally ridged cuticle made up of 8 layers, a hypodermis and a layer of longitudinal muscle cells which are divided into 4 sectors by the hypodermal cords. There is a characteristic cephalic inflation of the cuticle in both sexes. The structure of the body wall in the anterior half of the female is similar to that of the male. In the posterior half of the female the cuticle is not ridged and has 7 layers; the longitudinal muscles are reduced in number and the lateral hypodermal cords increasingly extend dorsally and ventrally along the length of the posterior part of the nematode and come to occupy most of the lateral sectors of the body. The possible significance of these modifications in the structure of the female nematode are discussed.
The cell biology of sexual development in Plasmodium
Authors: Sinden R. E.
Published: June 2009

This review examines the sexual development ofPlasmodiumspp. particularly relating the ultrastructural organization of their cells to the limited, though rapidly expanding, body of metabolic and biochemical studies. Thus it is hoped the article may provide a useful background of information for those undertaking studies on the sexual parasites with the objective of developing methods for the immunological and chemo-therapeutic control of malaria transmission. These objectives, however, should not dominate our clear recognition that the three phases of sexual development, gametocytogenesis, gametogenesis and fertilization contain within them examples of control and assembly of organelles without peer amongst eukaryotic cells.