bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructure and cytochemistry of the tegument ofOrthocoelium scoliocoeliumandParamphistomum cervi(Trematoda: Digenea)
Authors: Sharma P. N. , Hanna R. E. B. 
Published: June 2009

AbstractThe tegument ofOrthocoelium scoliocoeliumandParamphistomum cerviwas examined using histochemical techniques and electron microscopy. On the basis of the distribution of acid and alkaline phosphatase (E.C. 3.1.3.2, E.C. 3.1.3.1), non-specific esterase (E.C. 3.1.1.1), cholinesterase (E.C. 3.1.1.7) and succinate dehydrogenase (E.C. 1.3.99.1) at light microscope level two distinct regions were recognized, an outer and an inner zone. Electron microscopy revealed that the tegument comprises an outer surface syncytium underlain by a thick subsyncytial zone and musculature. Deeper still occur the nucleated “tegumental cells”. The latter are in cytoplasmic continuity with the surface syncytium via vacuolated cytoplasmic trabeculae which traverse the muscle layers and the subsyncytial zone. Three types of tegumental cells each lacking mitochondria were observed. The T1cells synthesize discoid and electron dense T1bodies while T2cells produce oval and electron lucent T2bodies. The third type of tegumental cells apparently produce no secretory bodies and may represent an embryonic cell type. The surface syncytium contains T1and T2secretory bodies and is bounded apically by a plasma membrane invested externally by a fuzzy and filamentous glycocalyx. The surface syncytium lacks mitochondria and is traversed by infoldings of the basal plasma membrane. Beneath the surface syncytium the subsyncytial zone is largely comprised of fibrous interstitial material. This zone, which is particularly thick in the amphistomes, is traversed by trabeculae and extensions of underlying parenchymal cells which usually contain mitochondria and lysosomes. The subsyncytial zone overlies numerous circular and longitudinal muscle fibres. The absence of mitochondria and enzymes associated with active transport suggests that the amphistome tegument may be mainly specialized for protection of the worm against mechanical and chemical conditions prevailing in the rumen. Active uptake of nutrients is probably not a primary function.
Effects of praziquantel and oxamniquine on a Saudi Arabian strain of Schistosoma mansoni in mice
Authors: Ghandour A. M. , Banaja A. A. , Shalaby I. M. 
Published: June 2009

ABSTRACTThe prophylactic and curative effects of praziquantel and oxamniquine on a Saudi Arabian strain of Schistosoma mansoni in MF-1 mice were assessed. The drugs were administered orally. At 240 mg/kg praziquantel, there was a reduction of 89·1% in adult worm recovery and a marked reduction in tissue deposited eggs. The reduction in adult worm recovery after dosing with 50 mg/kg oxamniquine was 89·2%. At low doses (40 mg/kg praziquantel and 30 mg/kg oxamniquine) administered at 11 days, 5 days and 3 h before and 5, 21 and 49 days after infection, the reduction in adult worm recovery was 0·0%, 65·1%, 58·8%, 33·6%, 0·0% and 76·0% for praziquantel and 0·0%, 66·0%, 60·0%, 41·3%, 10·8% and 79·0% for oxamniquine. Numbers of lung schistosomula and the size of hepatic granulomata were also reduced.
Effect of flubendazole on the number of first-stage larvae of Angiostrongylus cantonensis released in the faeces of treated rats
Authors: Maki Jun , Yanagisawa Toshio 
Published: June 2009

ABSTRACTThe effect of flubendazole orally administered at 10 mg/kg/day for 5 consecutive days (the 11th, 20th or 40th post-infection) on the number of first-stage larvae (L1) of Angiostrongylus cantonensis released in the faeces of rats each infected with 40 third-stage larvae was determined. Faecal examination for 5 months, the period from medication to dissection of rats, showed that L1 release ceased in all the rats of medicated groups by about 1 week after the termination of dosing and resumed 1–2 months later in 86% of the rats which were dissected at the end of experiments with the recovery of adult worms of both sexes. Throughout the period of 5 months, about 2–4×104 L1/gram of fresh faeces was recorded in non-medicated control groups. There was a 38–79% reduction in adult worms at the dissection. Microscopic examination of the uteri of the remaining adult worms and lung tissues of rats confirmed no normal egg production in the adult worms from rats of medicated groups, except the rats with the resumption of faecal L1 release.
Antifilarial activity of intravenous suramin and oral diethylcarbamazine citrate on subperiodic Brugia malayi in the leaf-monkey, Presbytis cristata
Authors: Mak J. W. , Lam P. L. W. , Choong M. F. , Suresh K. 
Published: June 2009

ABSTRACTThe known filaricides, suramin and diethylcarbamazine citrate, were tested against subperiodic Brugia malayi infection in the leaf-monkey, Presbytis cristata. As expected, intravenous suramin at 10 mg/kg daily × 5 days or 17 mg/kg weekly × 5 weeks, did not show any microfilaricidal activity, but substantially reduced the recovery of live adult worms to 50·6% and 13·6% of controls respectively. Oral diethylcarbamazine citrate at 6 mg/kg daily × 6 or 10 days reduced final microfilarial counts to 30% of initial counts four weeks post-treatment and adult worm recovery was reduced to 4·5% and 0% of controls respectively. Although the antifilarial activity of these drugs against the infection in this non-human primate model appears to be similar to that seen in man, these results have to be confirmed using larger groups of animals.
Apparent absence of genetic differences among species of Teladorsagia (Nematoda: Trichostrongylidae)
Authors: Andrews R. H. , Beveridge I. 
Published: June 2009

ABSTRACTThe technique of allozyme electrophoresis was applied to three species of Teladorsagia present in sheep to determine the extent of genetic variation among species. Thirty-four enzyme loci were established of which 22 were invariant and 12 were shown to be polymorphic. No fixed allelic differences were detected among the species and the level of polymorphism was within the range found commonly between populations of a single species. Therefore, the genetic data support breeding data and existing morphological evidence that T. circumcincta, T. davtiani and T. trifurcata as currently recognized do in fact belong to a single species.
On the biological and biochemical nature of cloned populations of Strongyloides ratti
Authors: Viney M. E. , Matthews B. E. , Walliker D. 
Published: June 2009

ABSTRACTSeven geographically varied isolates of Strongyloides ratti were cloned. Each clone was examined for the degree of homogonic development of the free-living generation and by enzyme electrophoresis. Considerable variation was found between the clones in the degree of development that was homogonic. In Contrast, the clones were indistinguishable by enzyme electrophoresis.
Cryptocotyle lingua in mullet, Chelon labrosus; significance of metacercarial excretory proteins in the stimulation of the immune response
Authors: Matthews R. A. , Matthews B. F. 
Published: June 2009

Abstract‘O’ group mullet, Chelon labrosus. were experimentally infected with Cryptocotyle lingua (Heterophyidae) by tail dip in a suspension of cercariae. Metacercariae were excised after 1 and 24 hours and prepared for TEM and post-embedding immunogold labelling. Antisera to cercariae of C. lingua were raised in adult mullet by natural infection via the skin and by intra-peritoneal injection of sonicate. The membrane-bound vesicles within the syncytial lining of the metacercarial excretory vesicle were found to be intensely antigenic with both antisera: the epidermal secretory bodies type 5 within the cystogenousglands gave a positive response. Penetration gland contents were not found to be antigenic with either antiserum. Discharge of the membrane-bound vesicles coinciding with both the reorganization of the lining of the metacercarial excretory vesicle and with cyst wall formation appears to be of significance in the initiation of the host immune response. That the term ‘excretory vesicle’ in Digenea may be a misnomer is discussed in the light of current information regarding the wide range of functions attributed to this structure.
The effect of infection with Schistosoma margrebowiei on the growth of Bulinus natalensis
Authors: Raymond K. , Probert A. J. 
Published: June 2009

AbstractThree age groups of Bulinus natalensis, immature, mature but not yet egg-laying and mature egg-laying, were infected with miracidia of Schistosoma margrebowiei. The growth of infected, exposed but showing no signs of infection, and uninfected control groups, were examined at weekly intervals for ten weeks post exposure. Snails exposed to infection when immature, even in the group where no patent development ensued, showed a statistically significant reduction in growth and this was evident as early as 2–5 weeks post exposure. When infection occurred at the stage prior to egg-laying a significant reduction in growth was seen but only in the group which developed a patent infection. This was also the case for the egg-laying group although the reduction in growth was only significant in the final three weeks of the experiment. Thus in all three age groups, growth rate was reduced and the infected snails were significantly smaller at the end of ten weeks compared with the controls. The reasons for these effects are discussed.
Density-dependent effects on establishment of Necator americanus and Ancylostoma ceylanicum
Authors: Norozian-Amiri S. M. B. , Behnke J. M. 
Published: June 2009

AbstractThe relationships between the number of infective larvae (L3s) to which animals were exposed and the establishment of A. ceylanicum and N. americanus in hamsters were examined. There was no evidence of density-dependent constraints on the establishment of A. ceylanicum in the range 10–1000 larvae, but an experiment in which the range was extended to 1500 L3s gave a significant negative correlation between the magnitude of the infecting dose and percentage establishment. Even so the percentage reduction was relatively small, approximating to 0·89% per 100 larvae administered, and in practice density-dependent constraints on establishment are unlikely to affect experiments with this species in which much lower doses (<250 L3) are generally employed. The range of doses for N. americanus L3s was smaller (10–400). Of the four experiments reported, two gave a significant reduction of establishment with increasing dose and two did not. When the data was split into low doses (<100 L3s) and high doses (>100 L3s), falling establishment with increasing dose was only detected in the lower dose range. There was no difference in the establishment when doses of 100 L3s were compared with 250 or 400 L3s. On balance, it was concluded that density-dependent constraints on establishment of N. americanus in hamsters were not marked and would have little significant effect on experiments utilizing fewer than 200 L3s (approximately 7·6% reduction between 10 and 200 L3s). These results are discussed in relation to host regulation of hookworm burdens.
Infectivity, growth and distribution of preovigerous adults of Echinostoma caproni in ICR mice
Authors: Manger P. M. , Fried B. 
Published: June 2009

AbstractAll 23 6–8-week old outbred female ICR mice, each fed 100 metacercarial cysts of Echinostoma caproni, were infected on days 2, 4, 6, and 8 postinfection (PI) with a mean of 45 worms/host. To examine worm distribution in the mouse, the small intestine was divided into five equal sections (segments 1–5 beginning with the pylorus). Worms were found mainly in segments 3 and 4 and were never found in segment 1. Mean body area of worms fixed in 10% neutral buffered formalin (NBF), hot alcohol-formalin-acetic acid (AFA) and aceto-carmine increased slowly until day 4 and then rapidly until day 8 PI. There was a significant difference in the mean body area of worms fixed in hot AFA, NBF, and aceto-carmine on all days except 4 and 6. Distinction of the ovary and ootype was apparent by day 6 and uterine cooling was observed by day 8 PI. Only 2 of 50 worms showed eggs in the uterus on day 8 PI.
Strongyloides ratti: dissociation of immunological memory of the protection against tissue migrating larvae and intestinal adult worms in mice
Authors: Abe T. , Yoshimura K. , Nawa Y. 
Published: June 2009

AbstractImmunological memory generated by infection with S. ratti was studied separately in the migratory and intestinal phases in mice. Protection against reinfection in the migratory phase was 96–98% at 2 weeks but significantly decreased to 60% at 12 weeks after the primary infection. However, protection in the intestinal phase was 96% even 12 weeks after the primary infection. Recall of immunity against the intestinal phase persists for longer than that against the migratory phase in mice.
The antibody response in serum, intestinal wall and intestinal lumen of NMRI mice infected with Echinostoma caproni
Authors: Agger M. K. , Simonsen P. E. , Vennervald B. J. 
Published: June 2009

AbstractGroups of mice (NMRI) were infected with 0.6 and 25 metacercariae of the intestinal trematode Echinostoma caproni. An enzyme linked immunosorbent assay (ELISA) was developed for measuring the specific IgM, IgG and IgA antibody responses in serum, small intestinal tissue and small intestinal lumen of the mice, by using a crude adult E. caproni antigen. In infected mice, significant levels of IgM were measured in the sera from day 14 after infection and of IgG and IgA from day 28 after infection. Early in the infection, the mean level of serum IgM was higher in 6-worm infections than in 25-worm infections. Late in the infection, higher mean levels of IgA were reached in the serum of mice with high than in those with low dose infections. The onset of appearance of antibodies in the tissue of the small intestine reflected the picture seen in the serum. For IgM, and to a lesser degree for IgG, the highest mean antibody levels appeared in the posterior sections of the small intestinal wall, where also the parasites were located. The mean level of IgA, however, was uniform throughout the length of the small intestinal tissue. High levels of specific IgA were detected in the lumen of the small intestine on day 28 after infection, especially in the anterior sections, where only few parasites were located. No specific IgM or IgG could be detected in the intestinal lumen on this day. The results are related to the intestinal location and the pattern of expulsion of E. caproni in the mouse host.
Embryogenesis in Litomosoides carinii from pyridoxine deficient cotton rats
Authors: Beg M. A. , Storey D. M. 
Published: June 2009

AbstractPyridoxine (vitamin B6) deficiency was induced in cotton rats which were then infected with the filarial parasite Litomosoides carinii. Embryogenesis was assessed microscopically in worms taken from pyridoxine deficient cotton rats and from various categories of control animals. Embryogenesis was retarded in worms from pyridoxine deficient hosts and more abnormal embryos were present in such worms than in those from control animals.
Partial characterization of proteolytic enzymes in different developmental stages of Ostertagia ostertagi
Authors: de Cock H. , Knox D. P. , Claerebout E. , de Graaf D. C. 
Published: June 2009

AbstractProteolytic enzymes present in extracts of third (L3) and fourth (L4) stage larvae and adults of the cattle nematode Ostertagia ostertagi were defined on the basis of pH optima and proteinase inhibitor sensitivity in spectrophotometric assays using azocasein and elastin-orcein as protein substrates. Evidence that different classes of proteinases are expressed in a stage specific manner was provided by the contrasting pH optima and inhibitor sensitivities shown by the enzymes in the different parasite stages. Stage specificity was confirmed by gelatin-substrate analysis. In addition, proteolytic activity was sought in the excretory/secretory products (ES) of the L4 following simple in vitro culture. Contrasting pH and inhibitor sensitivities as well as gelatin-substrate analysis showed that different proteinases were present in somatic L4 extracts and L4 ES products. The secreted proteinases may be useful targets for serodiagnosis or vaccination.
Fasciola hepatica: the infection rate and the development of redial generations in Lymnaea truncatula exposed to miracidia after experimental desiccation and activation in water
Authors: Rondelaud D. 
Published: June 2009

AbstractAdult Lymnaea truncatula were subjected to 10 days of experimental desiccation and then remained in water for 1 or 8 days before each was exposed to a single miracidium. The infection rate was lower in these snails than in infected controls that were not exposed to stress (52–54% vs 73%). The redial burden clearly decreased in stressed snails (18–25 rediae per snail) than in controls (43 rediae). This numerical decrease concerned essentially: i) live independent rediae of the first generation and the first cohort of the second generation, and ii) dependent rediae of subsequent generations. Mature rediae were more numerous in the first cohort of the second generation than in the other generations. Desiccation before exposure limited the size of the redial burden but placement in water for 8 days just after the stress attenuated the effects of this factor.
Field observations concerning infection of Lymnaea palustris by Fasciola hepatica
Authors: Dreyfuss G. , Moukrim A. , Rondelaud D. , Vareille-Morel C. 
Published: June 2009

AbstractFasciola hepatica miracidia were experimentally introduced into five sites colonized by Lymnaea palustris over a period of 4 or 6 years. In the first four ponds, a progressive increase in the prevalence of the spring-generation juvenile snails was observed (from 0.4 to 18.1%), with a corresponding increase in the shell height of infected snails (from 3.6 to 7.8 mm). In the fifth habitat, the pond dried in 1990 causing the prevalence to drop as compared with the initial values and to subsequently increase in 1991–1992.
The functional anatomy of the anterior end ofSkrjabinoptera goldmanaefrom Australian agamid lizards
Authors: Jones H.I. 
Published: June 2009

AbstractFour muscle groups are responsible for the eversion and retraction of the apical denticles and enlarged pseudolabia inSkrjabinoptera goldmanae(Nematoda: Physalopteridae), which occurs in the lizardsChlamydosaurus kingii, Pogonaspp. andVaranus gouldiiin Australia. These muscles enable the nematode to bury its anterior portion in the gastric submucosa of its hosts. They comprise three sets which are derived from the somatic musculature and are inserted in the oesophagus and associated organs, and a fourth set of muscles which appears to be derived from the muscular oesophagus itself. These accessory muscle groups are described and illustrated, and from this their mode of action in everting and retracting the pseudolabia is derived. Possible selection pressures which led to their evolution are reviewed.
Structural and functional comparison of trematode haemoglobins
Authors: Rashid K.A. , Haque M. , Siddiqi A.H. 
Published: June 2009

AbstractHaemoglobins from three different species of trematodes (Gastrothylax crumenifer, Paramphistomum epiclitum and Isoparorchis hypselobagri) and their respective hosts were digested with papain. Peptides so produced were separated on 10–15% SDS-PAGGE. The probability of coincidence of the peptides was analysed statistically. Oxygen affinity curves of trematode haemoglobins were found to be a rectangular hyperbolic. The Hill coefficient values of all the trematode haemoglobins were found to be 1. The P50 values, at 25°C in 0.2M phosphate buffer pH 7.4, ranged from 0.8 to 1.6 mmHg.
Prevalence of schistosomiasis and other intestinal helminth infection among senior primary school children in Makenene Sub-Division, Cameroon
Authors: Akufongwe P.F. , Onwuliri C.O.E. , Titanji V.P.K. , Okwuosa V.N. 
Published: June 2009

AbstractA study was carried out in four vifiages of Makenene Sub-Division some 85 km north-west of Yaounde, between November 1993 and March 1994 to assess the prevalence and intensity of schistosomes and other helminth infections among senior primary school pupils aged 9–16. An extensive questionnaire was used to collect sociodemographic information and information on water-related activities.The overall prevalence of S. mansoni infection was 228 (23.6%) while S. haematobium infection was practically non-existent 03 (<1%). Infection rates with intestinal nematodes were very high, up to 98% in some villages. Prevalence rates of schistosomiasis varied significantly (P<0.05) between vifiages with the highest (36.2%) recorded in Makenene. Infections with other parasite species encountered were significantly different (P<0.01) while a marked association was observed between water contact activities and the distribution of S. mansoni infections. However, S. mansoni infection intensities were not significantly different (P>0.05) between those with a history of previous infection and treatment and those without.
Characterization of DNA restriction profiles and rRNA gene restriction fragment length polymorphisms of Proteocephalus exiguus and P. neglectus from geographically distinct regions
Authors: Turceková Ľ. , Kráľová I. 
Published: June 2009

AbstractThe total DNA of two morphologically similar cestode species of the genus Proteocephalus parasitizing coregonid and salmonid fish, P. exiguus La Rue, 1911 and P. neglectus La Rue, 1911, was compared. The methods of DNA analysis involved digestion of the total DNA with restriction endonucleases and Southern blotting hybridization with the ribosomal DNA probes pSM 889, pSM 389 and pSM 890. No inter-specific variation was found between the two proteocephalid species. Distinct differences in RFLP patterns were recorded between two geographically distinct population of P. neglectus after BspRI digestion; after EcoRI digestion and following hybridization with the 32P-labelled probe pSM 890 and after BamHI digestion and hybridization with the 32P-labelled probe pSM 889. The high degree of genetic similarity revealed in the two Proteocephalus spp. could be a further argument for the conspecifity of both taxa.
Changes in the excretory bladder ultrastructure during the morphogenesis of Levinseniella brachysoma metacercariae
Authors: Galaktionov K.V. , Malkova I.I. 
Published: June 2009

AbstractFor the first time the development of the excretory system Levinseniella brachysoma metacercariae (Trematoda: Microphallidae) obtained experimentally from Gammarus oceanicus has been described. The bladder wall of 8-day post-infection (P.I.) larvae consists of a syncytium covered with microvilli. Its cytoplasm contains well-developed rough endoplasmic reticulum (RER), free ribosomes, small oval dense mitochondria and numerous large membrane-bounded (about 5 μm in diameter) spherical granules. Later the size of the excretory bladder and the number of nuclei and RER cisternae increases. The large spherical granules disappear completely but spherical dense bodies (up to 4 μm in diameter) devoid of limiting membranes appear. The bladder lining forms thick columnar projections directed towards its lumen. Accumulations of microlamelli occur only on the lumen surface between adjacent projections. By the 42nd day P.I. the bladder wall has two separate components: the columnar projections and the syncytium between them.