bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implantation of adult Onchocerca gutturosa into laboratory rodents
Authors: Sinnary K. A. El , Bianco A. E. , Williams J. F. 
Published: June 2009

SUMMARYAdult males and females ofOnchocerca gutturosawere implanted into the peritoneal cavity of mice, and their survival was determined at intervals thereafter by post-mortem examination. Ten of 17 animals receiving males dissected free of bovine host tissues contained live parasites at necropsy up to 4 months later. Female worms digested free from connective tissue by collagenase did not survive well, even though they appeared motile and intact before implantation; only 2 were alive 10 days later in 2 of 16 recipients. When males and females still contained within connective tissue capsules were implanted they survived for up to 2 months, and microfilariae were detected transiently in the skin of 2 recipient mice. The results suggest the feasibility of maintaining adultO. gutturosain rodents by this means, provided exposure of worms to enzymes used to free them from host tissue is avoided.
Biology of gyrocotylideans with emphasis on reproduction, population ecology and phylogeny
Authors: Williams H. H. , Colin Judith A. , Halvorsen O. 
Published: June 2009

SUMMARYThe Gyrocotylidea is a group of platyhelminths comprising only a dozen or so species which have been placed in three genera,OyrocotyleDiesing, 1850,AmphiptychesGrube and Wagener in Wagener, 1852 and Gyrocotyloides Fuhrmann, 1930. All species are highly specific to chimaeroid fish, a small group of present-day holocephalans, and are restricted to the spiral valve intestine of these hosts.
Babesia vesperuginis:natural and experimental infections in British bats (Microchiroptera)
Authors: Gardner R. A. , Molyneux D. H. 
Published: June 2009

SUMMARYBabesia vesperuginisis described from blood of two species of British bat:Pipistrellus pipistrellusandMyotis myslacinus. Reticulocytes appeared significantly elevated in blood films ofP. pipistrellusinfected withB. vesperuginiscompared with uninfected laboratory-maintained bats or apparently uninfected wild-caught bats. Infected captive bats had significantly enlarged spleens.B. vesperuginiswas transmitted by inoculation of infected blood to 5 uninfected captiveP. pipistrellus. The course of infection followed a pattern of a rising parasitaemia accompanied by a rise in reticulocytes, followed by a fall in parasitaemia to low (<0·1%) or undetectable levels. When sacrificed, theBabesia-infected bats had significantly lowered blood haemoglobin, significantly raised white blood cell counts and enlarged spleens compared to uninfected bats. Attempts to transmit the parasite to irradiated and athymic ‘nude’ mice by inoculation of infected blood were unsuccessful. The experimental results and observations of infected wild bats indicate the potential pathogenicity ofB. vesperuginisto bats. It is likely that the vector ofB. vesperuginisisArgas vespertilionisbecause no Ixodid ticks were found onP. pistrellus.
The response toSchistosoma bovisin normal and T-cell deprived mice
Authors: Murare H. M. , Agnew Alison , Baltz Marilyn , Lucas S. B. , Doenhoff M. J. 
Published: June 2009

SUMMARYNormal and T-cell deprived mice have been compared in their response to infection withSchistosoma bovis. The deprived mice survived longer than comparably infected, immunologically intact controls, despite an increased longevity of the adultS. bovisworms in the former animals giving rise to higher tissue egg densities. The reduced pathology in deprived mice was due to inhibition of T-cell dependent granuloma formation around tissue-bound schistosome eggs, with concomitantly decreased tissue disruption as evidenced by smaller spleens and lower circulating transaminase concentrations. These observations onS. boviscontrast with the greater morbidity and earlier mortality induced byS. mansoniin T-cell deprived mice, the latter due to an hepatotoxic potential ofS. mansonieggs that is expressed in the absence of the host immune response. The absence of hepatocyte damage aroundS. boviseggs in deprived mice indicates that this schistosome lacks such a toxin, and this could explain why duringS. bovisinfection synthesis of the two acute-phase proteins, complement C3 and serum amyloid P-component (SAP) here seemed less T-dependent than has previously been found duringS. mansoniinfection of mice. In a time-course experiment the hypergammaglobulinaemia induced byS. bovis, and the specific IgG antibody response against egg antigens were significantly T-cell dependent during the early stages of patency. Similarly, in most experiments assayed once between 9 and 11 weeks afterS. bovisinfection, deprived mice had significantly reduced hypergammaglobulinaemias, and reduced specific IgM and IgG antibody responses against both worm and egg antigens.
Effects of a series of infections ofOstertagia circumcinctaon gastric secretion of sheep
Authors: Anderson N. , Blake R. , Titchen D. A. 
Published: June 2009

Sheep which had been either previously infected withO. circumcinctaor maintained worm-free, were surgically prepared with separated fundic pouches and abomasal cannulae and subsequently infected with 20000O. circumcinctalarvae three times weekly.A reduction in food intake and increases in total acid output from the pouches and plasma pepsinogen levels were evident in both groups of sheep 4 days after repeated infections commenced; effects which increased in severity after 12 or more days. Except for a transient period of slight failure, previously infected sheep retained the capacity to acidify their abomasal contents whereas previously worm-free sheep lost this capacity. These changes were reversed between 2 and 7 days after treatment with thiabendazole (88 mg.kg−1).Secretory capacity of the fundic pouches was tested with histamine (40 μg.kg−1), the histamine antagonist (burimamide 8mg.kg−1) and atropine (100 μg kg−1). Ostertagiasis reduced or abolished the stimulatory effects of histamine. An increase in secretion volume and acid output was obtained after food was freshly provided, even though as little as 25 gm was consumed. Atropine and burimamide both caused a profound decrease in pouch secretion and acid output.These data are consistent with the hypothesis previously stated that in ostertagiasis the hypersecretion from fundic pouches is due to increased levels of circulating gastrin.
The feeding behaviour of larvae, nymphs and adults of Rhipicephalus appendiculatus
Authors: Tukahirwa E. M. 
Published: June 2009

The pre-feeding and feeding periods of larvae, nymphs and adults of Rhipicephalus appendiculatus on rabbits (Oryctolagus cuniculus) were investigated. Larvae and nymphs required at least 8–9 days after hatching and moulting respectively before they could attach and start feeding, while adults required at least 6–9 days. But longer periods of starvation improved the proportion of ticks that successfully fed.After attachment, there was always an initial period of slow feeding, which was followed by a phase of very rapid feeding before the engorged ticks detached from the host. Larvae detached 4–5 days after attachment, nymphs detached after 5–6 days and adults detached 7–9 days after attachment.
Superoxide dismutase fromAscaris suum
Authors: Sanchez-Moreno M. , Monteoliva M. , Fatou A. , García-Ruiz M. A. 
Published: June 2009

SummaryThree superoxide dismutases (SOD) (EC 1.15.1.1) were detected in homogenates ofAscaris suum. Each of the three forms of SOD was purified by a sequence of multiple differential centrifugations, ammonium sulphate precipitation, ion-exchange chromatography and G-75 Sephadex column chromatography. The three forms of SOD were present in different cellular locations; one in the cytoplasmic fraction, sensitive to cyanide and hydrogen peroxide, and two in the mitochondrial fraction, one of which was cyanide sensitive. The SOD forms presented clear differences in their electrophoretic patterns. The sexual organs of females showed the highest SOD activities of all the tissues examined. The finding of such high levels of superoxide dismutase inA. suumreflects the importance of this enzyme in the metabolism of this helminth parasite.
Characterization of coccidial proteins by two-dimensional sodium dodecyl sulphate–polyacrylamide gel electrophoresis
Authors: Sutton C. A. , Shirley M. W. , Wisher M. H. 
Published: June 2009

SummaryTwo dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (2D SDS–PAGE) has been used to produce ‘fingerprint’ maps of the proteins from each of the 7 species ofEimeriawhich infect the chicken. All 7 species could be identified from their array of polypeptides but few differences were detected between strains of the same species. Alterations to the polypeptide array associated with the stage of sporulation of the oocysts were observed. lodination of sporozoites, 2D SDS–PAGE, autoradiography and immunoblotting techniques were combined to identify polypeptides with a surface moiety and those which were antigenic.
Origin, kinetics of circulation and fatein vivoof the major excretory–secretory product ofAcanthocheilonema viteae
Authors: Harnett W. , Worms M. J. , Kapil A. , Grainger M. , Parkhouse R. M. E. 
Published: June 2009

SummaryThe excretions-secretions (E-S) ofAcanthocheilonema viteaeconsist mainly of one product, molecular weight 62 kDa. This molecule is synthesized during the vertebrate phase of the parasite life-cycle and is first detectable in the E-S of L4 parasites. It is cross-reactive with E-S of human filarial parasites as a consequence of possessing a phosphorylcholine (PC) moiety. The 62 kDa molecule has been employed as a model for the study of the origin and fate of filarial E-S. Immunohistological analysis has shown the molecule to be located predominantly in the parasite gut. Transplantation of adult female [S] methionine pulsed worms into uninfected jirds resulted in the radio-labelled secreted 62 kDa antigen being detected in the bloodstream within 4 h by SDS–PAGE/immunoprecipitation analysis. The systemic half-life of the molecule as estimated by clearance of injected, purified I-labelled material was measured in naive and infected jird hosts.
The role of parasite fecundity and longevity in the success of Trichostrongylus tenuis in low density red grouse populations
Authors: Shaw J. L. , Moss R. 
Published: June 2009

SummaryThe prevalence of the caecal threadworm Trichostrongylus tenuis in red grouse in the north of Scotland was high despite low grouse densities. Prevalence, intensity and aggregation of threadworms was higher in old than in young grouse. Infections were long-lasting: populations of adult worms could survive for over 2 years in grouse, with little mortality. Parasite egg output decreased with the age of a worm population, largely as a result of a decrease in the fecundity of ageing female worms. Seasonal variations in worm fecundity were also evident.However, there was no evidence of an intensitydependent decrease of worm fecundity with increasing worm numbers in either captive or wild grouse. The long life and high reproductive capacity of T. tenuis probably contribute to its effective transmission and high prevalence.
A hybrid gene to express protein epitopes from both sporozoite and merozoite surface antigens of Plasmodium falciparum
Authors: Holder A. A. , Lockyer M. J. , Hardy G. W. 
Published: June 2009

SummaryThe DNA coding for parts of the repetitive amino acid sequence of the Plasmodium falciparum circumsporozoite protein has been spliced to a sequence encoding part of the precursor to the major merozoite surface antigens, to produce a hybrid gene. Expression in Escherichia coli produces a protein with antigenic determinants from both malaria proteins. Antibodies raised against the expressed material react with both a peptide derived from the circumsporozoite repeat sequence, and the merozoite surface molecule. Hybrid molecules of this type may be the basis of a malaria vaccine.
Excreted/secreted products of developing Taenia saginata metacestodes
Authors: Joshua G. W. P. , Harrison L. J. S. , Sewell M. M. H. 
Published: June 2009

SummaryExcretions and secretions (ES) and somatic components of 4, 8, 12 and 16-week-old Taenia saginata metacestodes were biosynthetically radio-isotope labelled by incubating the larvae in the presence of [35S]methionine. Despite their small size, 4-week-old metacestodes produced as much isotope-labelled ES/parasite as older metacestodes, indicating a proportionately greater metabolic activity of the parasite at this age. In situ the 4-week-old metacestodes were surrounded by a marked granulomatous cellular infiltrate which had largely resolved around 8-week-old metacestodes. Examination of the isotope-labelled ES by SDS-PAGE revealed distinct age-specific components from 4- and 12-week-old metacestodes and other ES components which were produced by all the ages of metacestodes examined. In comparison the labelled somatic components were conserved. Antigenic characterization of the ES by immunoprecipitation against a panel of clinically defined bovine sera combined with SDS-PAGE analysis, identified some highly immunogenic parasite products and others which did not elicit an antibody response demonstrable by immunoprecipitation. These components are of interest in relation to the host/parasite relationship, to the construction of diagnostic assays for the detection of T. saginata cysticercosis, and to the immunity that cattle develop against this parasite.
Schistosoma mansoni: evidence that ‘non-permissiveness’ in 129/Ola mice involves worm relocation and attrition in the lungs
Authors: Elsaghier A. A. F. , Knopf P. M. , Mitchell G. F. , Mclaren D. J. 
Published: June 2009

Summary129/Ola mice resemble WEHI 129J mice in that around 70% of the individuals in any given population resist a primary infection withSchistosoma mansoni. Squashed-organ autoradiographic tracking of [Se]selenomethionine-labelled parasites has shown that the kinetics of worm migration in 129/Ola mice follows the expected pattern, and that all rodents harbour essentially similar numbers of worms on day 14 post-infection. Combined lung and liver worm recovery techniques have revealed, however, that segregation of mice into ‘permissive’ and ‘non-permissive’ individuals can first be detected on day 20. ‘Non-permissive’ mice are characterized by the absence of schistosome eggs at all times in the liver parenchyma and, in consequence, lack the attendant manifestations of pathology; they do, however, harbour a few stunted worms in the liver and significant numbers of adult schistosomes in the pulmonary vasculature. Histological analysis of sectioned lung tissue from such animals indicates that some lung-located schistosomes feed, pair and lay eggs. Nevertheless, eosinophil-enriched inflammatory reactions develop around such worms and the parasites themselves exhibit various manifestations of trauma, ranging from minor vacuolation to gut herniation and extrusion. The phenomenon of ‘non-permissiveness’ thus involves retardation of worm development in the liver and, in consequence, relocation of the parasites to the lungs, where they become subject to host effector responses.
Portal shunting and resistance to Schistosoma mansoni in 129 strain mice
Authors: Coulson P. S. , Wilson R. A. 
Published: June 2009

SummaryThe integrity of the hepatic portal vasculature was examined, relative to the resistance to Schistosoma mansoni observed in 68°0 of 129/Ola mice. The passage of microspheres to the lungs, following their injection via the superior mesenteric vein, indicated the presence of shunts in the majority of both naive and infected mice. There was a negative association between shunting of microspheres to the lungs and paucity of liver worms at 28/35 days post-infection. Schistosomula accumulated in the livers of resistant mice at a slower rate than in susceptible animals, and after day 21 relocated to the lungs. Many lung schistosomula injected via the superior mesenteric passed immediately to the lungs; the shunts thus greatly reduce the probability of trapping in the liver. Some parasites migrated back from the lungs, successfully lodged in the liver and began to feed on blood. Latex infusion demonstrated the location of large intrahepatic connections between the portal and hepatic veins. We suggest that as these liver worms grow, migrating upstream into progressively larger vessels, they reach the connections, pass out of the hepatic portal system, and relocate to the lungs. The presence of the natural shunts thus accounts for the resistant status of the mice.
Analysis of a genetic cross between Trypanosoma brucei rhodesiense and T. b. brucei
Authors: Gibson W. C. 
Published: June 2009

SummaryTwo trypanosome clones, representing East and West African homozygotes at 2 isoenzyme loci (T. b. rhodesiense MHOM/ZM/74/58 [CLONE B] and T. b. brucei MSUS/CI/78/TSW 196 [CLONE A]), were cotransmitted through tsetse flies and the resulting trypanosome populations checked for the presence of non-parental karyotypes by pulsed-field gel electrophoresis. Ten clones isolated from these populations proved to have 5 different recombinant genotypes by analysis of nuclear and kinetoplast DNA (kDNA) polymorphisms. It is inferred that genetic exchange occurred between the 2 trypanosome clones in the fly, as previously reported for 2 other T. brucei spp. clones by Jenni and colleagues. For the most part, the hybrid clones shared many characteristics with both parents and their genotypes were consistent with segregation and reassortment of parental alleles. The least amount of genetic material exchanged was kDNA alone. Regarding the mechanism of genetic exchange, several hybrid clones had identical and unique nuclear DNA polymorphisms, but different kDNA type. Assuming that the same reassortment of nuclear markers is unlikely to occur by chance, these clones most probably arose from a predecessor carrying both types of kDNA.
Spatial and temporal heterogeneity in the population dynamics ofBulinus globosusandBiomphalaria pfeifferiand in the epidemiology of their infection with schistosomes
Authors: Woolhouse M. E. J. , Chandiwana S. K. 
Published: June 2009

SummaryPopulations ofBulinus globosusandBiomphalaria pfeifferiwere studied in a river habitat in Zimbabwe over a period of 12 months. Data were obtained on the prevalences of infections ofSchistosoma haematobium(alsoS. mattheei) andS. mansonirespectively. Population parameters showed the following patterns for both snail species. (1) A patchy distribution correlated with the distributions of aquatic plants. (2) Life-expectancies of only a few weeks. (3) Recruitment rates correlated with water temperature and showing a distinct seasonal peak. (4) Spatial variation in recruitment. (5) A redistribution of snails during the rainy season. Epidemiological parameters showed the following patterns. (1) Large seasonal variations in the prevalence of patent infections. (2) Evidence from size-prevalence curves that suggests a variable force-of-infection from man to snail, correlated with water temperature. (3) Prevalences of infection that were higher in the vicinity of (±60 m from) major water contact sites. Local prevalences of infection forB. globosussometimes exceeded 50% and may have approached 100% if pre-patent infections are included. Snail numbers may limit transmission at these locations. Attention is drawn to the need to make field observations at an appropriate spatial scale and also to the implications for the effectiveness of focal snail control as a means of reducing transmission.
Studies on motilityin vitroof an ectoparasitic monogenean,Diclidophora merlangi
Authors: Maule A. G. , Halton D. W. , Allen J. M. , Fairweather I. 
Published: June 2009

SummaryAn isometric transducer system has been used to record spontaneous motor activity inDiclidophora merlangi in vitro. Motility took the form of either continuous irregular contractions or bursts of activity with intermittent quiescent periods. Maximal activity was recorded from specimens at 5–8 °C in artificial sea water (ASW). Decerebration induced a period of enhanced motility which subsided within 1 h. Water turbulence elicited large, rapid contractions of the longitudinal body musculature which did not habituate or fatigue. Induced water turbulence at frequencies higher than 3/min inhibited spontaneous movements, resulting in a progressive reduction in contraction amplitude and, eventually (30/min), the abolition of any response to water movement. The neurotoxin tetrodotoxin failed to modify worm activity. Excitatory responses from both intact worms and strip preparations were obtained with 5-hydroxytryptamine, dopamine and noradrenaline, but aminergic antagonists failed to block their effects. Atropine stimulated contractility, whereas the effects of acetylcholine or carbachol were inconsistent. Nicotine increased muscle tone but the effect was unaltered by atropine, mecamylamine ord–tubocurarine. Muscarine, hemicholinium, neostigmine and eserine were without apparent effect.
Schistosoma mansoni:analysis of the humoral and cellular basis of resistance in guinea-pigs vaccinated with radiation-attenuated cercariae
Authors: McLaren D. J. , Delgado V. S. , Gordon J. R. , Rogers M. V. 
Published: June 2009

SummaryThis study addresses the humoral and cellular basis of specific acquired immunity in the guinea-pig irradiated vaccine model of schistosomiasis mansoni. Rodents vaccinated with 500 gamma-irradiated cercariae and then splenectomized 4·5 weeks later showed a 33% reduction in resistance to challenge as compared to vaccinated animals or vaccinated/sham splenectomized controls. Serum harvested from once vaccinated individuals conferred modest levels of resistance upon naive recipients in some experiments, but transfer was not achieved consistently. Serum from vaccinated and thrice boosted rodents (Vbbb) routinely transferred around 45% immunity, however, provided it was given in 4 ml aliquots on day 9 post-challenge; Vbbb serum thus transferred 50% of donor immunity. Interestingly, multiple doses of this protective serum given on and either side of day 9 did not enhance the protection achieved with a single 4 ml aliquot. Neither peripheral lymph node cells nor splenocytes from the polyvaccinated serum donors were able to transfer resistance to recipient guinea-pigs and they failed to augment the protection achieved with Vbbb serum. Food-pad testing revealed no correlation between delayed hypersensitivity responses and immunity to challenge in vaccinated guinea-pigs. Although polyvaccine guinea-pig serum successfully protected homologous recipients, it failed to protect mice when administered either at the time of challenge (the optimal schedule for transfer of polyvaccine mouse serum), or around day 9 (the optimal schedule for guinea-pigs). Similarly, guinea-pigs could not be protected with polyvaccine rat serum that conferred 75% resistance upon naive recipient rats.