bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal effects on the seasonal dynamics of Paradiplozoon homoion (Bychowsky & Nagibina, 1959) parasitizing roach, Rutilus rutilus (L.)
Authors: Höglund Johan , Thulin Jan
Published: June 2009

The prevalence and relative density of the monogenean Paradiplozoon homoion, were monitored over one year in populations of roach, Rutilus rutilus, captured in a thermally raised artificial lake located outside a nuclear power station and in a nearby reference locality. Recruitment of P. homoion started earlier in the warmer lake. A temporal shift of the life-cycle was thus observed but there were no differences between the total prevalence or the total relative density of the parasite in the two areas. Since there is no evidence of parasite-induced host mortality, or for the development of protective immunity, the main regulatory process in the heated area are most likely an increased mortality due to reduced thermal tolerance of the adult parasite.
Observations on the post-mortem migration of nematode larvae and its role in tissue digestion techniques
Authors: Prociv Paul
Published: June 2009

The importance of larval viability in relation to the success of recovery techniques and to the interpretation of histological and migration studies was tested using mice infected with Toxocara pteropodis, T. canis and T. cati. Little difference was found in total numbers of viable larvae recovered from tissues incubated for 18 hours in 0·85% saline, 2% trypsin or 1% pepsin, but the rates of larval egress did vary. The recovery of dead larvae by digestion techniques was much lower. Larvae migrated in tissues undergoing fixation, which influenced histological findings. Larvae of T. canis did not undergo significant peritoneal migration in acutely-infected mice, but did penetrate their intestinal walls in large numbers within 4 hours of death. The implications of these findings in experimental studies are discussed.
Trapping of large numbers of larvae in the livers ofToxocara canis-reinfected mice
Authors: Sugane Kazuo , Oshima Tomoo
Published: June 2009

Congenially athymic nude mice (BALB/c-nu/nu) and BALB/c-nu/+ were infected with 500 embryonatedToxocara caniseggs. Six weeks later they were reinfected with the same number of eggs. The liver and other organs were examined for numbers of 2nd-stage larvae at 2,4, and 6 weeks after reinfection. Far more larvae were trapped in the liver after reinfection than after the primary infection but fewer were found in the livers of BALB/c-nu/nu than in BALB/c-nu/+ mice.
Onchocerciasis in British cattle: a study ofOnchocerca gutturosaandO. lienalisin North Wales
Authors: Trees A.J. , McCall P.J. , Crozier S.J.
Published: June 2009

Onchocerca gutturosaandO. lienalisinflections in British cattle were studied by examination of cattle post-mortem originating from North Wales and Cheshire (north west England). In 463 adult animals, the microfilarial (mf) prevalence was 28·5%. In 95·3% of the inflected animals, gravid worms could not be found at either the ligamentum nuchae or the gastro-splenic omentum. Dermal mf at the head were identified asO. gutturosaon the basis of their highly significant assocation with the presence of gravidO. gutturosaat the ligamentum nuchae, which were found in only 3·2% of cattle. Mfs were isolated from different skin sites and from adult worms and a minimum of 10 mfs from each isolate were examined for width and acid phosphatase (AP) staining pattern. The width ofO. gutturosadermal mf was <4 μm (4 isolations), narrower than of putativeO. lienalismf isolated from umbilical skin of cattle without evidence ofO. gutturosa, which were in 20/22 isolations >4 μm wide. The dermal mf were also distinguished on the basis of different AP staining patterns which, for each species, correlated closely with that of hatched intrauterine mf from their respective adult female worms. Based on the criteria of morphology and AP staining patterns the mf species prevalences in the survey population were estimated asO. lienalis24·1% andO. gutturosa2·2%, with a further 2·2% of cattle inflected with both species. The results indicate that the predilection site of adultO. lienalisis not the gastro-splenic omentum. In North Wales, the distribution of the two species was different;O. lienaliswas widely distributed in all cattle rearing areas both lowland and upland, whereasO. gutturosawas largely restricted to valleys close to major rivers.
Infections of forest rat filaria, Breinlia booliati, in neonate and juvenile laboratory white rats
Authors: Ho Beng-Chuan , Chew Lai-Ming , Yap Eu-Hian , Singh Mulkit
Published: June 2009

The kinetics of Breinlia booliati infection in 3 inbred rat strains (Lewis, Wistar and Sprague Dawley) were investigated. One group of rats was infected as neonates (less than 24 hours of age) with third-stage larvae of B. booliati and the other group was infected as juveniles (4 weeks of age). The results showed that infection in the neonates were significantly different from the infection in the juveniles. The 60 rats infected as neonates, when necropsied between 8 to 10 months postinfection, yielded adult worms. The 2 neonatal infection groups of Lewis and Wistar strains showed highest susceptibility to the infections. The mean prepatent period was 85 days. Ninety to 95% of the infected rats were patent with microfilaraemia and a large percentage (33 to 47%) of them had high microfilaraemia counts exceeding 3000 mff/20 mm3 of blood and larger sizes (mean 157·11 mm for female adult worms and 61·88 mm for male adult worms. The adult worms were distributed equally in both the pleural (57%) and peritoneal cavity (43%). In most aspects, the neonatal infection group of the Sprague-Dawley strain was intermediate in susceptibility between the 2 neonatal infection groups of the Lewis and Wistar strains and the 3 juvenile infection groups. In contrast to neonatal infection groups, the 3 juvenile infection groups exhibited low infection rates (37%, 58% and 47% for the Lewis, Wistar and Sprague Dawley strains respectively), longer prepatent periods (mean 101 days), lower recovery rates (2 to 4%), lower adult worm loads (mean 0·4 to 0·8 female worms, and 0·2 to 0·8 male worms per rat), and smaller sizes (mean 141·24 mm for female adult worms and 53·75 mm for male adult worms). Forty-four to 57% of these infected rats harboured either single male or single female adult worms in the body cavity. Most (92%) of the adult worms recovered from the juvenile infection groups resided in the pleural cavity and the remaining 8% were recovered from the peritoneal cavity. Microfilaraemia could be detected in only 3/20 Lewis rats, 5/20 Wistar rats and 5/20 Sprague Dawley rats. The mean peak microfilaraemia of the 3 pooled juvenile infection groups was 632 mff/20 mm3 of blood, ranging from 7 mff/20 mm3 to 1856 mmf/20 mm3. Our results indicate that the susceptibility to B. booliati infection in white rats is both genetic and age-associated. The responses of the 2 distinct infection groups to B. booliati infections are discussed.
Comparative analysis of amino acids of three species of Gangesia (Cestoda: Proteocephalata)
Authors: Nanda Sunita , Bhalya Anjali , Gairola Damyanti , Malhotra Sandeep K. , Capoor V. N.
Published: June 2009

A total of 21 amino acids were detected in the present investigations on three species of Gangesia (Cestoda: Proteocephalata) viz. G. bengalensis Woodland, 1924, G. hanumanthai Seth & Capoor, 1982 and G. sanehensis Malhotra et al., 1981. The study was conducted in a sub-humid region around Allahabad, India. The implications of amino acid utilization in metabolic activities of fish tapeworms have been discussed.
The effect of praziquantel on the ultrastructure ofSchistosoma margrebowiei
Authors: Awad A. H. H. , Probert A. J.
Published: June 2009

The effect of various concentrations of praziquantel at different time intervals post-treatment on the ultrastructure ofSchistosoma margrebowieiusing scanning and transmission electron microscopy has been examined. The major changes involved blebbing of the entire surface tegument of both sexes (although more marked in males) together with vacuolation of the basal membrane accompanied by the development of membraneous whorls. These effects were progressively more marked with increased concentration and time of exposure resulting in severe erosion of the tubercles and collapse of the sensory organelles. Exposure of the underlying tegumental tissue resulted and paralysis and contraction of the suckers and neck region was apparent. Disruption of the subtegumental musculature and the appearance of vacuolation and membraneous whorl formation were seen. The gastrodermis was similarly affected and the S4 cells of the vitelline gland showed protein disruption of the vitelline droplets. Host cells were seen adhering to the surface of the worms following drug treatment and the synergism between PZQ and the action of the hosts immune system has been discussed.
Nonspecific immunomodulation influences resistance of mice to experimental infection with Mesocestoides corti and Ascaris suum
Authors: Heřmánek J.
Published: June 2009

The influence of nonspecific immunomodulation on the course of experimental infection was examined in larval cestodosis (Mesocestoides corti) and ascaridosis (Ascaris suum) in mice. Immunosuppressive treatment (with azathioprine or hydrocortisone) resulted in a decrease of resistance in both models. The subsequent administration of T-activin to immunosuppressed mice led to the restoration of resistance to a level equal to that of untreated control mice. The administration of different immunomodulators partially protected mice against M. corti (T-activin. thymomodulin) or A. suum (T-activin. thymomodulin. thymosin fr.5. bursa-activin) infection. The protective effect of different treatments did not correlate with the level of specific antibody in the sera of infected mice. These results, which confirmed the decisive role of T-cell immunity in the resistance to the helminth infections, raise the possibility of the use of immunomodulators (thymic preparations) in the immunoprophylaxis of helminthoses.
In vitroeffect of larval stages ofAscaris lumbricoideson human blood clotting
Authors: Malla N. , Sofi B. A. , Ganguly N. K. , Mahajan R. C.
Published: June 2009

The effects of larval stages ofAscaris lumbricoideson human blood clotting was studiedin vitro. Extracts and excretory/secretory products of third-stage larvae (L3) and late third-stage larvae (LL3) cultured from ova obtained from infected patients were analysed for anti-coagulant activity. Prothrombin time (PT) was prolonged by the addition of either whole extract of L3/LL3or ES products of L3/LL3as compared to controls. Partial thromboplastin time with kaolin (PTTK) was also prolonged on the addition of either extracts of ES products of L3/LL3. The prolongation of PTTK was significantly higher with extracts/ES products of L3when compared to the extracts/ES products of LL3(p<0.005). Thrombin time (TT) was prolonged by extracts of L3/LL3and their ES products.
Molecular cloning of the cDNA encoding an immunodominant antigen ofDirofilaria immitis
Authors: Sun Shu-Han , Matsuura Tadashi , Sugane Kazuo
Published: June 2009

An immunodominant antigen ofDirofilaria immitiswas studied using recombinant DNA techniques. The mRNA fromD. immitisadult female worms was translated invitroand a major 34 k Da antigenic polypeptide product was demonstrated by immunoprecipitation. cDNA was synthesized from mRNA and a λ gt11 expression library was constructed and immunoscreened with dirofilariasis positive serum. A positive clone containing a nearly full length cDNA was isolated. The cDNA was 2415 bp in length and consider of a single open reading frame followed by a long 3' non-coding region of 1446 bp. The open reading frame of 969 bp encoded a polypeptide of 322 amino acids with a molecular weight of 34 400. A cDNA fusion protein synthesized by bacteria (Escherichia coliJM109) using the expression vector pGEMEX-1 was identified as an immunodominant antigen by absorption experiments and had no cross-reactivity with sera from patients with other filarial species.
Schistosoma curassoni Brumpt, 1931 and S. bovis (Sonsino, 1876) in cattle in northern Nigeria
Authors: Ndifon G. T. , Betterton C. , Rollinson D.
Published: June 2009

Schistosoma curassoni has been recovered from cattle in northern Nigeria. Rectal scrapings of 90 cows slaughtered at the Kano abattoir, Kano, Nigeria during March and April 1986 revealed a prevalence of 7·8% S. bovis and 2·2% S. curassoni. Further examination of the mesenteric and rectal veins of 502 cows showed that the overall prevalence of schistosomiasis was 31·1%. Local Bulinus globosus were infected successfully in the laboratory with S. bovis miracidia.
Immunization against experimental rabbit cysticercosis using liposome-associated antigen preparations
Authors: Craig P. S. , Zumbuehl O.
Published: June 2009

Rabbits were vaccinated once, by subcutaneous and intradermal injection, with sonicates of oncospheres (TpO) or conditioned media from in vitro maintained mature metacestodes (TpMcES) of Taenia pisiformis. Extracts were either incorporated into or mixed with unilammelar liposomes (reverse phase evaporative vesicles) or emulsified in Freund's Incomplete Adjuvant (FIA). Control groups received liposomes or FIA without antigen, or antigen preparation without adjuvant. Rabbits were challenged orally two weeks after vaccination with approximately 1500 eggs of T. pisiformis and necropsied eight weeks after challenge. A mean of 155 cysts was recovered from seven control rabbits. A 67% reduction in peritoneal cyst numbers was obtained in TpO–IFA vaccinated rabbits compared to 75% for the TpO–liposome entrapped group. The highest level of protection (86%) was obtained when TpO was mixed with but not entrapped in liposomes. Only 32% and 39% reduction in peritoneal cyst numbers was obtained after immunizing with the TpMcES preparation in liposomes or IFA respectively, however >85% of peritoneal metacestodes were dead (necrotic or calcified) and suggests a different immune response than occurs after vaccination with oncosphere extracts. Specific anti-oncospheral or anti-metacestode ES antibody (IgG) responses at two weeks post vaccination were similar in rabbits immunized with liposome or IFA associated extracts.
Vitelline gland histochemistry in the commensal temnocephalidParacaridinicola platei(Fernando, 1952) Baer, 1953, together with some notes on the egg
Authors: Breckenridge W. R. , Nathanael Shirani
Published: June 2009

Histochemical tests indicate the presence of tanning precursors namely protein, phenols and phenolase in the vitelline glands of the temnocephalidParacaridinicola platei. This suggests the occurrence of a tanned egg shell in this organism, a feature it shares with many other parasitic and free living platyhelminths. The large eggs are laid singly and are attached to the gill lamellae of the host.
Antigenicity of a proteolytic enzyme ofFasciola hepatica
Authors: Coles G. C. , Rubano D.
Published: June 2009

The possibility was examined of using a haemoglobinase released duringin vitroincubation of adultFasciola hepaticafor immunodiagnosis of fascioliasis. By SDS gel electrophoresis the enzyme appeared as two closely migrating bands with a molecular weight of approximately 27 000 daltons. After Western blotting the bands reacted with serum from rats infected withF. hepaticaand mice infected withSchistosoma mansoni. The enzyme was therefore not a good antigen for immunodiagnosis.
Early lymphocytic responses to Heligmosomoides polygyrus infections in mice
Authors: Parker S. J. , Inchley C. J.
Published: June 2009

Responses to parasite antigens were studied in three strains of mice, BALB/c, CBA and NIH, during the initial phases of a primary infection with the intestinal nematode Heligmosomoides polygyrus. Changes in the rate of in vivo cell division were analysed in mesenteric lymph nodes and spleens during the phases of larval maturation and adult establishment, and related to changes in organ size and cellularity. The nature of the proliferating cell populations was also investigated by flow cytometry, carried out on cell suspensions prepared at the time when larval development was complete. The variation in the ability of the strains of mice to become resistant to a challenge infection was manifest as only slight differences in their initial responses to infection. All three strains showed an increase in 125I-iododeoxyuridine incorporation in their mesenteric lymph nodes and spleen, and an increase in B cell frequency over that of T cells in the draining lymph nodes. Although lymph node weight in NIH mice continued to rise over a 4 week period, the majority of responses measured were short lived, peaking 10 to 14 days after infection. The low responder status of CBA mice was thus reflected in a transient and relatively small enlargement of lymphoid tissues, but their early proliferative responses to antigen were similar in scale to those of responder strains.
An insect, Sialis lutaria, as a host for larval Proteocephalus sp.
Authors: Kennedy C. R. , Nie P. , Rostron J.
Published: June 2009

Larvae of a species of Proteocephalus were observed in the intestines of larvae of Sialis lutaria (Insecta: Megaloptera) in a single locality at prevalence levels of up to 40% and over a period of three years. The cestodes were plerocerciform in character and up to 3 mm in length, having undergone some growth and development in the insect. Comparison of scolex morphology with that of adult Proteocephalus spp. obtained from fish in the same river suggests the most likely identity of the parasite is P. filicollis. Support for this suggestion came from the recovery of two parasites from experimentally infected sticklebacks, Gasterosteus aculeatus. This is the first record of a proteocephalid larvae from an insect, and so also from S. lutaria, and of a proteocephalid using a second, additional invertebrate host. The use of S. lutaria is so far known only from this one locality and may reflect the peculiar, but continuing, ecological conditions there, but it is suggested that the ability to use S. lutaria as an additional host may be associated particularly, though not exclusively, with parasites of sticklebacks.
Stage-specific expression of a developmentally regulated gene inDirofilaria immitis
Authors: Sun S. , Matsuura T. , Sugane K.
Published: June 2009

A previously reported cDNA clone encoding 34 kDa antigenic polypeptide ofDirofilaria immitis(λ cD34) was studied to elucidate the mechanism of stage-specific gene expression. The 34 kDa polypeptide was a larva-specific antigen and the mRNA was detectable in microfilariae but not in adult worms and eggs. The λ cD34 gene was not sex linked and was contained in the genome ofD. immitisat each stage. The stage-specific expression of the developmentally regulated gene inD. immitismay be controlled primarily at the mRNA level.
Echinostoma caproni and E. trivolvis alter the binding of glycoconjugates in the intestinal mucosa of C3H mice as determined by lectin histochemistry
Authors: Fujino T. , Fried B.
Published: June 2009

Mouse (C3H) mucosal glycoconjugates were examined in normal small intestines and intestines infected with Echinostoma caproni, or E. trivolvis using six different fluorescein-conjugated lectins: Triticum, vulgaris agglutinin (WGA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin I (RCA-I). Glycine max soybean agglutinin (SBA), Dolichos biflorus agglutinin (DBA), and Arachis hypogaeu peanut agglutinin (PNA). The expression of lectin-binding sites and the intensity of the binding of lectins in the mouse small intestines were changed by infection with the echinostomes. Specific differences in the reaction to glycoproteins were clearly observed between the mouse intestines infected with E. caproni and those infected with E. trivolvis. In E. caproni infection, binding of most of the lectins to the villi was remarkably reduced in accord with the villous atrophy and loss of goblet cells. In contrast, in E. trivolvis infection, the binding of WGA, RCA-I and DBA was reduced in the microvillar surfaces, but binding of UEA-I and SBA were unchanged compared to the control intestines. The lectin binding to goblet cells in E. trivolvis-infected mice mostly increased. These observations may reflect the marked increase in goblet cells and the less severe damage in the villi of E. trivolvis infection compared to E. caproni infection. Most of the glycoconjugates were slightly reduced in the hyperplastic crypts except for N-acetyl glucosamine. It is possible that glucose metabolism in the host intestines infected with E. trivolvis was activated. resulting in an increase in the rate of mucin synthesis as well as qualitative changes in mucus, thereby mediating the expulsion of the worms.
Comparative spectral, electrophoretic and isoelectric properties of trematode haemoglobins
Authors: Rashid K. A. , Haque M. , Siddiqi A. H.
Published: June 2009

A comparative studs of the spectral, electrophoretic and isoelectric properties of the haemoglobins of three trematodes. Paramphistomum epiclitum. Gigantocotyle explanatum and Gastrothylax erumenifer was carried out. A high absorption in the beta band region indicates that trematode haemoglobins have high oxygen affinities. Electrophoretic mobilities of all trematode and their host haemoglobins were different. The isoelectric points of trematode haemoglobins were found to focus in the acidic range except that of G. crumenifer haemoglobin I. which focused at an alkaline pH.
Prevalence of larval helminths in freshwater snails of the Kinmen Islands
Authors: Chao David , Wang Lian-Chen , Huang Tai-Chu
Published: June 2009

A survey of larval helminths in freshwater snails of Kinmen was conducted from 1986 to 1987. Parasitological examinations of a total of 726 live snails collected from 25 loci revealed that 20 of 80 Bithynia fuchsiana were infected with metacercariae of Echinostoma gotoi and 36 with metacercariae of other echinostomes. Among 57 Radix auricularia swinhoei snails, 27 were infected with echinostomes and with metacercariae of other flukes. Of 20 Cipangopaludina chinensis, 18 were found with larvae of echinostomes. Larval trematodes were also found in three of 37 Austropeplea ollula and two of 87 Gyraulus spirillus. Third-stage larvae of Parastrongylus cantonensis were found in Ampullarius canaliculatus (5/103), Sinotaia quadrata (20/141), Hippeutis umbilicalis cantori (1/70) and Gyraulus spirillus (2/87). Segmentina hemisphaerula were not infected. Cercariae of Centrocestus formosanus, Haplorchis pumilio and xiphidiocercaria were found in three, two and two specimens, respectively, of 37 Thiara tuberculata.
The development of new foci of echinococcosis in northern Israel: prevalence in domestic animals
Authors: Furth M. , Hoida G. , Nahmias J. , Greenberg Z. , Barzilay A. , Goldsmith R.S. , El-On J.
Published: June 2009

In a survey carried out in 1991–1992 in the town of Yirka in Northern Israel, 49 dogs were examined for Echinococcus granulosus infection and abattoir data, based on organs condemned for the presence of parasites, was collected. The presence of E. granulosus by arecoline test was demonstrated in 7 (14.2%) of the dogs examined, but no parasites were found in the intestines of five stray dogs shot in the area. A survey of sheep slaughtered in the local abattoir during a one-month period revealed Echinococcus cysts in 10% of the 255 animals examined. No Echinococcus parasites were detected in 21 dogs examined 3 months after the initiation of praziquantel treatment. Echinococcosis seems to be a very serious public health problem in Israel and a control programme needs to be given a high priority.
Genomic variability within laboratory and wild subspecies ofHeligmosomoides polygyrus
Authors: Abu-Madi M.A. , Reid A.P. , Lewis J.W. , Hominick W.M.
Published: June 2009

Genomic DNA extracted from laboratory and wild subspecies of the trichostrongyle nematodeHeligmosomoides polygyruswere compared using RFLP and DNA/DNA hybridization techniques. Eight restriction endonuclease digests of the genomic DNA of the two subspecies were hybridized with heterologous ribosomal DNA probes and the total radio-isotope labelled DNA of the laboratory subspecies. DNA hybridization of the two subspecies ofH. polygyrusyielded different banding patterns when probed with the rDNA clones inPvuII digests and when total genomic DNA was used as the probe inHind III andPvuII digests. The remaining hybridization profiles of both subspecies were identical.
Ultrastructure of the digestive system of adult Sanguinicola inermis
Authors: McMichael-Phillips D.F. , Lewis J.W. , Thorndyke M.C.
Published: June 2009

The alimentary tract of adult Sanguinicola inermis Plehn, 1905 (Digenea: Sanguinicolidae) was studied by transmission electron microscopy. A highly developed muscular region, likely to be a modified sucker, is present anteriorly to the oesophagus. The tegumental oesophagus, on the basis of the characteristics of the surface cytoplasm, is differentiated into anterior, median and posterior regions with the apical cytoplasm of the median oesophagus drawn into extracellular vesicles from which arise surface knobs. The oesophagus leads to a cellular intestine composed of a single layer of epithelial cells. The apical surface of the intestine is drawn into short luminal projections and the intestinal cells contain numerous organelles and secretory granules. No host cells or cell debris were evident within the alimentary tract, although the intestinal lumen was filled with electron-dense material.
Results of a large scale onchocercosis survey in Enugu State, Nigeria
Authors: Nwaorgu O.C. , Ohaegbula A. , Onweluzo I.E. , Alo E.T. , Nweke L.N. , Agu M.L. , Emeh E.
Published: June 2009

The prevalence of onchocercosis was determined in three Local Government Areas (Ezeagu, Oji-River and Uzo-Uwani) in Enugu State, Eastern Nigeria between March 1989 and June 1990. Enugu State was shown to be mesoendemic for onchocercosis. A total of 7472 (26.9%) persons out of 27,831 examined were positive for skin microfilariae. There was no significant difference in infection rates between males (27.6%) and females (26.2%). Of the 118 villages surveyed only five had no inhabitant with skin microfilariae. There was a progressive increase of prevalence to the second decade of life, although 96.6% of cases with skin microfilariae had only a light infection. Onchocercomata prevalence was recorded as 27.3% which tallies with the prevalence of skin microfilariae at 26.9% hence onchocercomata prevalence may be used as a yardstick for predicting skin microfilariae prevalence.
Biology of Crassicutis cichlasomae, a parasite of cichlid fishes in Mexico and Central America
Authors: Scholz T. , Pech-Ek M.C.F. , Rodriguez-Canul R.
Published: June 2009

Field study on the biology of Crassicutis cichlasomae Manter, 1936 (Digenea: Homalometridae) was carried out in a small swamp in a limestone factory near Mérida, Yucatán, Mexico. Aquatic snails, Littorina (Littoridinopsis) angulifera, harbouring C. cichlasomae rediae, cercariae and metacercariae, served both as the first and second intermediate hosts. Feeding experiments confirmed the conspecificity of metacercariae from naturally infected snails with adults from naturally infected fish. Gravid C. cichlasomae worms were obtained from experimentally infected fish 19 days post exposure at 22–24°C. Examination of fish from the swamp in Mitza and other localities in the Yucatan Peninsula showed that the cichlids Cichlasoma urophthalmus and C. meeki were definitive hosts of C. cichlasomae. There was no pronounced preference of C. cichlasomae adults for the site of their location in the intestine of the definitive host; a slightly higher proportion (41%) of worms was only found in the anterior third of the gut. The time of miracidium development varied from 18.5 to 27.5 days; different temperature (20.1–35.7°C) or light/darkness regimes influenced only slightly the rate of embryonic development, with shorter development times at higher temperature (34.8–35.7°C) and constant darkness and/or light. With the exception of the sporocyst, all developmental stages are described and figured.
Separation of outer cysts from metacercariae ofFasciola giganticain an aqueous two-phase system
Authors: Yoshihara S. , Hazeyama M. , Kato H. , Goto N.
Published: June 2009

The outer cysts (Oc) ofFasciola giganticametacercariae (Mc) were separated in an aqueous two-phase system composed of polyethylene glycol and dextran in distilled water. A large number of separated Mc without Oc were recovered in the bottom layer rich in dextran in the system. Ten separated Mc in the layer were used to inoculate the mouse with a syringe and juveniles were recovered from the animals on the 14th day. When the number of juveniles recovered was compared with that from the mice infected orally with the same number of Mc, there was a significant difference between them (P <0.05). The former method is easier than the latter for inoculation.
Effect of ivermectin on infection with gastro-intestinal nematodes in Sierra Leone
Authors: Behnke J.M. , Pritchard D.I. , Wakelin D. , Park J.R. , McNicholas A.M. , Gilbert F.S.
Published: June 2009

Levels of intestinal nematode infections were assessed six months after a two year trial of ivermectin for efficacy against onchocerciasis had ended. In the trial the inhabitants of six villages in Sierra Leone were offered treatment with ivermectin or placebo at six monthly intervals for four rounds in total. Quantitative faecal egg counts were carried out on stool samples provided by 202 subjects, all of whom had received all four rounds of treatment, in two of the villages (Dodo and Mogibisi). These data were analysed by a novel procedure in which a 3-way ANOVA with negative binomial errors enabled village and host gender influences on the outcome of treatment to be identified. Necator americanus was the most common species showing an overall prevalence of 90% but a higher intensity in Mogibisi relative to Dodo, particularly among male subjects. Neither prevalence nor intensity of infection were altered in ivermectin-treated compared with placebo-treated subjects. Trichuris trichiura was the least common species with a prevalence of 15%. It was concluded that there was no significant protection from infection with this species among the ivermectin relative to the placebo-treated subjects. Ascaris lumbricoides, with an overall prevalence of 39%, was more common among female (50%) compared with male (27%) villagers. Prevalence was not significantly affected by ivermectin but the intensity of infection declined by 91.3% in Dodo whilst in Mogibisi intensity was only reduced by 14.6%. The results indicate that the long-term benefits of treatment of necatoriasis and trichuriasis with ivermectin are likely to be minimal whilst those of ascariasis will depend on the individual characteristics of local communities and may differ quite markedly within a limited geographical area. Possible explanations for the discrepancy in efficacy between villages are considered.
In vitro hatching of oncospheres of Taenia taeniaeformis using eggs isolated from fresh, frozen, formalin-fixed and ethanol-fixed segments
Authors: Negita T. , Ito A.
Published: June 2009

In order to establish a simple means of handling eggs of taeniid cestodes under non-biohazardous conditions, gravid segments of Taenia taeniaeformis were fixed in ethanol or formalin or were frozen. In vitro hatching of oncospheres was carried out by the 0.5% sodium hypochlorite method using eggs isolated from the nonviable and viable segments. No oncospheres hatched from formalized eggs, whereas almost all oncospheres hatched from all other eggs but the number of oncospheres recovered was highly variable. Oncospheres hatched from eggs isolated from frozen segments were highly fragile. The highest figures for in vitro hatching of oncospheres were recorded when eggs isolated either from segments fixed in 70% ethanol or from viable segments were used.
Zinc deficiency and host response to helminth infection: Echinostoma caproni infections in CBA mice
Authors: Bæk J. , Simonsen P. E. , Friis H. , Christensen N. Ø.
Published: June 2009

The effect of zinc deficiency on the response of CBA mice to infection with the intestinal trematode Echinostoma caproni was examined. Young CBA mice were allocated to one of three dietary groups: a group fed a zinc deficient diet ad libitum, a control group pair fed a zinc sufficient diet and a control group fed a zinc sufficient diet ad libitum. The mice on the zinc deficient diet gained significantly less weight than the pair fed controls. In primary infections with six E. caproni metacercariae followed over a period of 128 days, zinc deficiency delayed worm expulsion. In addition, zinc deficiency resulted in a prolonged IgM response, a delayed IgG response and an increased IgA response towards the end of the experiment. Resistance to challenge infection day 21 following a primary infection with 25 E. caproni metacercariae was slightly, but not significantly, affected by zinc deficiency.
Analysis of the prevalence of infection and associations between human gastrointestinal nematodes among different age classes living in the urban and suburban communities of Port Harcourt, Nigeria
Authors: Udonsi J.K. , Behnke J.M. , Gilbert F.S.
Published: June 2009

Fresh stool samples from 300 subjects presenting at out-patient clinics in two major hospitals in Port Harcourt were analysed for the prevalence and intensity of gastrointestinal (GI) nematode infections and 85.3% were found to carry at least one of the four species of GI nematodes recognized during the study. The most common species was Ascaris lumbricoides (54%), followed by Trichuris trichiura (43.7%) and Necator americanus (42.7%) and lastly Strongyloides stercoralis (33%). Peak prevalence for A. lumbricoides was among the ≤9 years age cohorts, whilst those for the remaining species all coincided among the 15–19 years age cohort. The frequencies of single, double and triple-species infection categories, across the species and within most of the specific combinations were lower than the expected frequencies calculated from overall prevalence data for each species. Observed cases of non-infected individuals and those carrying all four species were higher than expected, suggesting that a greater than expected subset of the population was free from infection, particularly among subjects ≥30 years old and another subset more prone to infection by all four species, predominantly among the age cohorts ≤29 years. N. americanus and T. trichiura were more commonly encountered among multiple species infection combinations than expected, but the intensity of the former declined as the number of other concurrently infecting species increased. In contrast, the intensity of infection with S. stercoralis increased as the number of other species increased. Positive associations between A. lumbricoides and T. trichiura, N. americanus and S. stercoralis, and T. trichiura and N. americanus were identified in respect of greater than expected co-occurrence of these combinations and significant positive correlations between their respective intensities of infection. These were related to specific age cohorts which were identified as particularly prone to multiple infections.
Evidence for specificity of Steganoderma formosum for its second intermediate host in the Northwest Atlantic
Authors: Marcogliese D.J.
Published: June 2009

Metacercariae of Steganoderma formosum Stafford, 1904 infected 17 of 358 Acadian hermit crabs (Pagurus acadianus) on the Scotian Shelf east of Nova Scotia, Canada, in the Northwest Atlantic Ocean in 1989, 1990 and 1995. Overall prevalence and abundance in P. acadianus on the Scotian Shelf were 5% and 0.4 metacercariae per crab, with a maximum intensity of 56. The highest prevalence (34%) and abundance (2.9) were recorded in the winter of 1989. All infected hermit crabs were greater than 9 mm in cephalothorax length. The parasite was not found in Acadian hermit crabs (n = 74) from Georges Bank, nor in any hairy hermit crabs (P. arcuatus and P. pubescens) on the Scotian Shelf (n = 808), on Georges Bank (n = 14), or in the northern Gulf of St. Lawrence (n = 87). A single sand shrimp (Crangon septemspinosa) of 1254 collected from the Scotian Shelf in 1989 and 1990 was infected with a metacercaria of S. formosum. None of 421 pink shrimps (Pandalus spp.) collected from the Scotian Shelf in 1989 and 1995 was infected. Male and female reproductive systems were well developed and spermatozoa were observed in the seminal receptacles of most parasites, suggesting that these metacercariae are progenetic. The distribution of the parasite among potential intermediate hosts suggests that S. formosum demonstrates greater specificity for its second intermediate host in the Northwest Atlantic than it does in the Pacific or in the Northeast Atlantic oceans.
Larval somatic antigens effective in inducing an IgG response and protection againstStrongyloides papillosusinfection
Authors: Ooba C. , Nakamura Y. , Taira N.
Published: June 2009

A serum IgG response toStrongyloides papillosusinfection was analysed in rabbits. IgG production was induced against 30–200 kDa larval somatic antigens and 21–160 kDa adult excretory/secretory (ES) antigens at 4 weeks postinfection. No immunoreactivity was detected between sera of infected animals and any proteins of larval ES and adult somatic antigens. Protection against larval challenge infection was investigated in rabbits immunized by primary infection and by intradermal inoculations of larval somatic and adult ES antigens. Primarily infected animals had 90% fewer or less worms from day 2 onwards after challenge, and lower faecal egg outputs after challenge, when compared with those in susceptible animals. Immunization with larval somatic antigens induced effective protection, showing 52.6–81.5% reductions in worm recovery from day 5 onwards after challenge, and lower faecal egg outputs after challenge. Systemic immunization with adult ES antigens failed to protect the animals against challenge. The possibility that resistance toS. papillosusreinfection is performed on the killing of migrating larvae in the early stages of infection is discussed. Systemic immune responses to larval somatic antigens might play an important role in the resistance.
Ligula intestinalis: interactions with the pituitary-gonadal axis of its fish host
Authors: Arme C.
Published: June 2009

I was delighted to be able to join with so many friends and colleagues, in writing this short paper to mark the retirement of Donald Lee. There are many outstanding milestones in Donald's career. However, I thought that I could perhaps draw special attention to his long and distinguished association with the British Society for Parasitology (BSP), and the journal, Parasitology. He was President of the BSP between 1978 and 1980 and, in recognition of his service to the Society and contributions to the discipline of parasitology, was elected an Honorary Member in 1980. Donald has also had a long association with Parasitology, as a member of the Editorial Board and as a frequent contributor. His first paper in the journal was published in 1958; it described the occurrence of Syngamus sp. in a fieldfare (Turdus pilaris) that had been accidentally killed. At the time of writing, his most recent publication, but I suspect not his last, was a biochemical study on proteins produced by Nippostrongylus brasiliensis, Nematodims battus and Ascaridia galli (Foster & Lee, 1996). Of course, Donald has published in many other journals and authored several books. However, if one considers only those papers published in Parasitology, they provide a record of intellectual vigour and curiosity that has remained undiminished throughout his career.
Variability of Fasciola infections in Lymnaea truncatula as a function of snail generation and snail activity
Authors: Rondelaud D. , Dreyfuss G.
Published: June 2009

Field investigations were carried out over a 4-year period in three farms of the Haute-Vienne department (France) in order to determine the prevalence of Fasciola hepatica infection in the annual generations of Lymnaea truncatula. Infection rates found in March were significantly lower than those recorded in July or in September (0.8% to 2.2% compared to 5.7% to 13.5% and 4.4% to 9.3%, respectively). They were always lower in overwintering snails than in other snail generations (summer generation in 1989,1990 and 1991; spring and summer generations in 1992). Experimental infections of L. truncatula by F. hepatica were performed to evaluate the characteristics of Fasciola infection with reference to snail generation and snail activity. Survival of summer generation snails at day 30 postexposure was significantly lower in snails collected in September than in those collected in May and June. In the winter generation of L. truncatula, snail survival was significantly higher in snails collected from December to March than in those from November. The prevalence of infection was significantly lower in snails collected in September (summer generation) than in those collected from December to March (winter generation). The duration of the prepatent period was significantly delayed in snails collected from January to March (a mean of 54.2 to 58.2 days instead of 43.1 to 49 days in the other groups), whereas that of the patent period was significantly shorter (5 to 9.3 days instead of 18.3 to 40.3 days, respectively). In snails collected from January to March, the number of metacercariae was significantly lower than that found from other snail groups (a mean of 21.5 to 42 metacercariae instead of 72.8 to 151.4 cysts, respectively). Fasciola infections of L. truncatula originating from spring and summer generations were more efficient than those from the winter generation of snails.
Comparison of the post-parturient rise in faecal egg counts of indigenous and cross-bred ewes
Authors: Singh S. , Yadav C.L. , Banerjee D.P.
Published: June 2009

The breed differences in post-parturient rise (PPR) in faecal egg counts in lambing ewes of different breeds naturally infected with Haemonchus contortus were compared. The ewes of Nali, 50% Nali × 50% Russian Merino/Corriedale and 37.5% Nali × 62.5% Russian Merino/Corriedale were treated with fenben-dazole while ewes of the above three breeds as well as 25% Nali × 75% Russian Merino/Corriedale, were kept untreated. Observations from 3 weeks before lambing to 12 weeks post-lambing at weekly intervals revealed that in treated ewes, egg counts of Nali did not differ significantly with 50% Nali whereas 37.5% Nali had significantly higher egg counts than those of Nali and 50% Nali. In untreated ewes egg counts of 50% Nali were significantly higher than that of Nali on some occasions, while 25% Nali had significantly higher egg counts than the other three breeds. None of the ewes from the Nali breed showed signs of haemonchosis, whereas few lambing ewes of the three Nali crosses (50%, 37.5% and 25% Nali) showed signs of haemonchosis and one ewe of the latter breed died.
An epidemiological survey of Echinococcus granulosus and other helminths in animal populations in northern Israel
Authors: Hoida G. , Greenberg Z. , Furth M. , Malsha Y. , Craig P.S. , Schantz P.M. , Sneir R. , El-On J.
Published: June 2009

In a survey carried out during the period May 1995 to November 1996, in communities of various ethnic groups in northern Israel, 206 dogs were examined for Echinococcus granulosus and other intestinal helminth parasites by arecoline hydrobromide purges and the coproantigen-ELISA. The arecoline test was performed close to the owners' homes, using plastic sheets secured to the ground. From 56 dogs examined in the Muslim town of Tamra, six (10.7%) were found to be infected with E. granulosus. Four of them also had a mixed infection of Taenia hydatigena and Dipylidium caninum (two dogs), and the remaining two dogs were infected with either D. caninum or Taenia pisiformis. An additional 18 dogs were infected with either T. pisiformis (eight dogs), D. caninum (seven dogs), or T. hydatigena (three dogs). Two of these dogs harboured mixed infections whereas the remaining 32 dogs were free of helminths. In the Jewish villages, none of the 150 dogs examined were infected with E. granulosus, although 26 (17.3%) were infected with D. caninum, four (2.7%) with Ancylostoma spp. and one (0.7%) with Toxocara canis. Only one of the 22 stray dogs and none of the 15 jackals examined were infected with E. granulosus. However, 21 (95.4%) of the dogs and 12 (80%) of the jackals harboured helminth infections, including: D. caninum (16 dogs and seven jackals), Ancylostoma spp. (five jackals), T. hydatigena (three dogs), and T. canis (one dog). Approximately 18% of the dogs and 33% of the jackals showed mixed infections with two or more of the above helminths. In the abattoirs, 52 (5.9%) of the 874 sheep and 33 (5.3%) of the 616 goats from 17 herds slaughtered in the Muslim and Druze villages were found to be infected with E. granulosus, compared with a 0% infection rate observed in 93 sheep from two herds in Jewish villages.
Antibody responses to fluke cysteine proteinases in Paragonimus- and Fasciola-infected rats
Authors: Ikeda T.
Published: June 2009

IgG and IgM antibody responses to fluke cysteine proteinases in Paragonimus ohirai- and Fasciola sp.-infected rats were followed by means of cystatin capture ELISA using fluke excretory-secretory products for 10 weeks after infection. The specific IgG antibodies were detectable at week 2 postinfection in all P. ohirai-infected and some Fasciola-infected rats. Levels of specific IgG antibodies increased rapidly between week 2 and 6, and slightly thereafter, in both infected groups. From week 3, specific IgG antibody levels were higher in Fasciola-infected than P. ohirai-infected rats. Sera from infected rats did not react with heterologous cysteine proteinases throughout the infection periods. In both infected groups, the kinetic patterns of specific IgM antibody responses were similar to those of specific IgG antibody responses although the ELISA levels of the IgM antibody responses were much lower. In abnormal infections with P. ohirai metacercariae x-irradiated at 2 krad, the specific IgG antibodies were detectable at week 2 postinfection with similar ELISA values to normal P. ohirai infection, but thereafter increased little. In infections with P. westermani, for which the rat is not a suitable host, even stunted worms induced a comparable specific IgG antibody response, although the response was lower than in normal infections with P. ohirai. These results indicate that cystatin capture ELISA can distinguish clearly between Paragonimus and Fasciola infections which show immunodiagnostic cross-reactivity and is useful even in the early stages of the infection and in the infection of unsuitable hosts.
Ultrastructure of the digestive and protonephridial systems of the metacercaria of Euclinostomum multicaecum
Authors: Ramasamy P. , Brennan G.P. , Stalin K.
Published: June 2009

The structure of the digestive tract of Euclinostomum multicaecum (Digenea: Euclinostomatidae) is unusual, comprising several main lateral caeca which extend posteriorly and further divide, giving rise to numerous smaller branches which are widely distributed throughout the fluke. These multicaeca presumably promote nutrient absorption during rapid and prolonged feeding directly following excystment. The caecal wall consists of a syncytial gastrodermal epithelium, bearing loop-like lamellae which extend into the lumen and enclose spherical inclusion bodies and presumably also, increase the absorptive surface area. There was no evidence of endo- or exocytosis, nor were lysosomes, phagosomes or residual bodies observed. The gut caeca are supported by a fibrous basal lamina and an underlying layer of muscle fibres, while parenchymal cells occupy much of the extracellular space. The protonephridial system resembles that observed in other digeneans consisting of flame cells and collecting ducts which join to form a bladder that opens externally through a single excretory pore. The syncytial epithelium of the collecting ducts is elevated by numerous lamellae while the basal lamina is highly infolded. The luminal contents of these ducts comprise bar-shaped crystalline structures, lipid droplets and electron-dense inclusion bodies. The excretory system is supported by a network of muscle fibres and parenchymal cells.