B Fried

..An additional aspect of this article is a review of the pertinent literature published from 1937 to 2007 on ageing and longevity of digeneans...

..Some mortality was noted in culture by day 5, but most organisms were still alive when the cultures were terminated on day 7...

..Excystation in vitro in AP at 41 degrees C is compatible with the fact that this organism establishes itself in the acid-pepsin environment of the proventriculus of avian hosts...

..A concentration of 10 mg l(-1) CuSO4 in Locke's-ASW (1:1) allowed for normal in vitro encystment within 48 h and these cysts were capable of excystation in a trypsin-bile salts medium...

..Exogeneous glucose added to ASW prolonged the survival of S. mansoni cercariae and increased infectivity in terms of worm recovery...

..caproni and S. mansoni. Increased snail activity associated with feeding behaviour was probably responsible for the enhanced cercarial sheds observed in this study...

..From 6 to 24 hr PI, 93-100% of the cercariae were recovered as metacercarial cysts in the snail tissue. Treatment of these cysts in the TB medium resulted in 96% excystation within 2 hr at 41 C...

..Because most of the implicated species are in the Echinostomatidae and Heterophyidae, emphasis in the review is placed on species in these families...

..caproni cercariae in Locke's solution:ASW (1:1) showed that encystment was optimal at 23 degrees C (78% encystment) and that it declined to 44% at 28 degrees C and became almost nil (0.02%) at 12 or 37.5 degrees C...

..In the in vivo studies, by 1 h PI, 59+/-5% of cercariae had lost their tails and only 4+/-1% of the cercariae were actively swimming in the multi-well dishes. At 3 h PI, 72+/-3% of the cercariae began to form cysts within the snails...

..Further studies are needed to determine if the egg viability of other species in the "revolutum" group follow that of E. caproni or E. friedi...

..We also showed that there was a significant decrease in body area and uterine egg counts in worms from the host that had the greatest number of worms compared to those that were obtained from hosts with lower worm burdens...

..The review examines mainly the epidemiology and pathology of these helminthic infections in humans and considers what we know about the mechanisms associated with the carcinogenicity of these three trematodes in humans...

..Treatment of the FBT mentioned in this review consists of various regimens of praziquantel, except for F. hepatica where the drug of choice is triclabendazole...

..trivolvis were seen in the stomachs of the chaetogasters. The protective action of the chaetogasters on the transmission of the cercariae of E. trivolvis and Z. lunata to second intermediate hosts in the wild awaits further study...

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..The mean +/- SE of eggs/uterus per worm (n = 10) was 243 +/- 6. This strain of mouse will be suitable to study the effect of long-term survival on the host-parasite relationship of E. caproni in Balb/c mice...

..We concluded that LM alone underestimated the viability of cysts and that determination of cyst viability was more accurate under assessment by chemical excystation...

..lunata and the armatae xiphidiocercaria to ORO-positive droplets in the excretory system of Ribeiroia sp. Rediae and sporocysts contained ORO-positive material in the body wall and in the space between cercariae...

..However, the lipophilic fraction of the SCW extract caused significant hatching. Substances in SCW significantly increase hatching of E. caproni miracidia, but details on what these compounds are remain obscure...

..1% glucose and in Locke's 1x plus 1% hen's egg yolk. Significant survival of excysted metacercariae in Locke's 1x supplemented with either 0.1% proline, 0.1% threonine, or 0.1% serine did not occur...

..Mebendazole and arprinocid were ineffective in eliminating worms at 1 or 2 days post drug administration...

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..Mebendazole and arprinocid were ineffective in eliminating worms at 1 or 2 days post drug administration...

..The E. trivolvis-R pipiens tadpole model is suitable for the study of host-parasite relationships of echinostome larvae in a cold-blooded vertebrate host...

..caproni were significantly larger than those of E. trivolvis. Morphometric analysis can be used to distinguish structural differences in closely related allopatric species of Echinostoma...

..When these extracts were placed on agar plugs in the bioassay, the lipophilic fraction, but not the hydrophilic fraction, was mainly chemoattractive...

..We found that triacylglycerol and cholesteryl ester levels decreased significantly as infection progressed...

..i. than that of worms on the control diet. An isocaloric diet deficient in the B vitamins had a detrimental effect on the growth of E. caproni in ICR mice...

..revolutum and E. trivolvis, the findings reported here show that body area and organ size can be used to distinguish these closely related species...

..i. Cercariae encysted in the kidney-pericardium of the snails. Encysted metacercariae could be excysted in vitro in an alkaline trypsin-bile salts medium or in vivo when fed to domestic chicks...

..05) in whole infected versus whole uninfected snails. Variations in the present results compared with other studies reflect intrinsic differences in the larval trematode-snail systems used...

..Snail size was a factor in mortality associated with echinostome cercarial penetration and encystment...

..Published information on the molecular biology of this organism does not exist. The organism is in need of new research efforts at all levels of organization from the molecular to the community...

..Collectively, these data indicate that Balb/c mice with 7-wk S. mansoni infection possess splenic T cells with altered chemotactic activity and that the alterations may be a consequence of the granulomatous response in the liver...

..Since Z. lunata is a potential foodborne trematode for humans and animals, it is important to determine suitable ways to control or kill these cysts...

..Worms from group C were more widely distributed in the small intestine than those from group B. Crowding effects associated with the high dose infection were clearly demonstrated in E. caproni from ICR mice...

..Nevertheless, cercariae survived longer in 1% glucose than in either 0.0, 0.1 or 0.5% glucose; but only at 23 h were any differences statistically greater (one way ANOVA, P < 0.05)...

..In conclusion, in vitro excystation data and morphometric light microscopic studies were useful in determining specific differences in the metacercariae of these 2 closely related allopatric species of 37-collar-spined Echinostoma...

..Glucose added to ASW extended the survival time of E. caproni cercariae but decreased their ability to infect snails or move in a linear direction...

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..glabratta snails are also sufficient to kill the cercariae and excysted metacercariae of these digeneans but not the encysted metacercariae, which may be protected by their cyst walls...

..The concentrations of glucose and maltose were significantly reduced in both uninfected-estivated snails and infected-estivated snails...

..No qualitative differences in neutral lipids and phospholipids in shell or plasma samples were found between infected vs uninfected snails...

..The phenomenon of spontaneous excystation in Z. lunata after in vitro encystment in a hypertonic medium appears to be reported for the first time in digeneans...

..05), with about twice the amount of PE in mice infected with E. caproni relative to the uninfected mice. No significant differences in any of the neutral lipid classes were found between infected and uninfected samples...

..05) in the methyl oleate fraction at 6 and 7 weeks PI relative to the uninfected controls. Neutral lipid profiles of urine may serve as an indicator of experimental infection of echinostomes in mice...

..Variations in the results of the two studies reflect intrinsic differences in the larval trematode-snail systems used...

..Eggs were fully developed by 3 wk post-incubation and miracidia hatched in the ASW. Laboratory-reared H. trivolvis snails were not available to attempt miracidia infections with Z. lunata ...

..Survival of infected versus uninfected neonatals was also examined for 7 days. Neonatals exposed to 10 cercariae showed a significant decrease in survival at 6 and 7 days PI when compared with uninfected controls...

..007) compared with the controls but not when compared with the infected-starved snails. Aestivation or starvation had a significant effect on the concentration of certain lipid classes in the DGG of B. glabrata infected with S. mansoni...

..The limited information on specific histochemical studies on these spines is also reviewed. Lastly, an examination of the few papers that have considered structure and function of collar spines is given...

..glabrata patently infected with S. mansoni suggests that these acids are utilized by the sporocysts and cercariae in the snail tissue, or that the infection stimulates reduced production or increased utilization by the snail tissue...

..00504 +/- 0.0014 and 0.00254 +/- 0.00033, respectively, in the DGG of infected snails. The differences in values between infected and uninfected snails were not statistically significant (Student's t-test, P > 0.05)...

..Beyond these times, there was a marked decline in egg viability. We suggest that WCs should not be stored for longer than 4 months in Locke's 1:1 at 4 degrees C to obtain optimal embryonation and hatching of E. caproni...

..trivolvis. Variations in the results of our study compared with others reflect intrinsic differences in the species of echinostome used...

..The review includes a list of researchers and their addresses who currently maintain such life cycles...

..Variations in the results of our study compared with others reflect intrinsic differences in the larval trematode-snail systems used...

..0229 and 0.0163, respectively, for worms incubated in DI water. Our findings suggest that E. caproni adults may leak amino acids for osmoregulation in hypotonic environments...

..Some helminthic substances, especially the cytokines, have respiratory and anti-allergic effects, and may therefore become useful as therapeutic modalities for many atopic and allergic disorders...

..glabrata. The hypercalcification hypothesis, i.e., larval trematodes induce an increase in the calcium concentrations in the shells of their snail hosts, was not upheld in any of the snail-larval digenean systems studied herein...

..Neutral and polar lipid levels were also quantified in P. bridgesii fed lettuce and yolk. Significantly higher amounts of triacylglycerols were detected in the digestive gland-gonad complexes of snails maintained on the egg yolk diet...

..polygyrus=high), but not IL-10. Concurrent malaria infection also suppressed helminth-associated IL-4 responses, indicating that immunologic counter-regulation occurs during co-infection with malaria and intestinal helminths...

..Moreover, significant worm age-host species interactions were found for body area, ovarian area, ventral sucker area, and anterior and posterior testicular areas...

..Malaria parasite prevalence and anemia were similar between co-infected and malaria only-infected mice, which suggested that enhanced malaria parasite transmission was due to helminth-induced modulation of host responses...

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..These observations are consistent with heme crystal formation by a hematophagous parasite within a non-vertebrate intermediate host...

..Our results indicate the fact that early inflammatory responses could be important for the establishment of E. caproni chronic infections in highly compatible hosts...

..In vivo, worm burden reductions of 100% were achieved with single oral doses of praziquantel, artesunate, and artemether at 50, 700, and 1,100 mg/kg of body weight, respectively...

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..Taken together, these results suggest that imported T. patialense may spread to various indigenous natural and cultured fish populations, with ensuing potential harm to these populations...

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..In contrast, the worm expulsion appears to be related to increases in local IgG2a levels...

..g., Cryptosporidium oocysts) able to resist standard disinfection applied to drinking water...

..Following this coverage, we include a final section on the important topical literature on selected trematodes in families other than the six mentioned above...

..Accumulation of these bacteria on the surface of encysted metacercariae probably contributed to a decreased cyst viability of E. caproni...

..In contrast, low levels of E. caproni seroantigens were detected in rats only. These observations may reflect the differences in local inflammatory responses induced by E. caproni in each host species...

..Comparison of the present findings with those recorded for other digeneans suggests that muscle organisation and innervation patterns in trematodes are highly conserved...

..Our results show that this assay can also be used to monitor the course of echinostome infections...

..We suggest that these echinostomes be considered as species in the Echinoparyphium recurvatum complex, until further morphological and molecular studies be done on this group...