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At least 19 recordsLinked to original sources

[Participation of Codiella troscheli (Mollusca: Prosobranchia) in the Metorchis albidus (Trematoda; Opisthorchidae) life cycle].

Investigating Mollusca prosobranchia of the Bithyniidae family in the water reservoirs of the Novosibirsk Region in 1994-1998 first revealed that Codiella troscheli had the trematode Metorchis albidus (Braun, 1893). The species affiliation of the trematode was experimentally verified. This paper presents the results of studies of the seasonal and daily emission of M. albidus cercariae and data on their longevity in the environment, on the ability of the cercariae to live in fish and that of metacercariae in the body of a definitive host. The studies have indicated that not only the trematode Opisthorchis felineus, but also C. troscheli may develop in the C. troscheli mollusks, which should be taken into account in both describing the natural foci of opisthorchiasis and diagnosing opisthorchiasis and metorchiasis.

Animals↗

Specific and common antigens of Clonorchis sinensis and Opisthorchis viverrini(Opisthorchidae, Trematoda).

The antigenic characterizations and serological reactions of human liver flukes, Clonorchis sinensis and Opisthorchis viverrini, were analyzed by immunoblot. The antigenic profiles of the crude extract of Clonorchis contained major proteins of 8, 26-28, 34-37, 43, and 70 kDa, and those of Opisthorchis 34-37, 43, 70, and 100 kDa. Of these, the 8, 26-28 and 34-37 kDa bands of Clonorchis and the 100 kDa of Opisthorchis were major components of each excretory-secretory antigen. The 8 and 26-28 kDa bands were specific to Clonorchis but the 100 kDa of Opisthorchis cross-reacted with the sera of clonorchiasis, and the 34-37, 70 and 100 kDa bands cross-reacted with sera of other helminthiases. The frequency and intensity of the immunoblot reactions were positively correlated with the intensity of the liver fluke infection.

Animals↗

[Influence of environmental factors on the infection rates of fishes and shellfishes by trematodes of the Opisthorchidae family in the Krotovaya Lyaga Lake].

The relationship of the annual trends in the infection of crucians (Carassius carassius) (L.) with Opisthorchis felineus metacercariae, in that of verkhovkas (Leucasplius delineatus) (Hackel), and in that of lake minnows (Phoxinus percnurus) (L.) with O. felineus and Metorchis billis to the environmental factors under natural fluctuations of the level of water and under the man-made effects on the water regime of the reservoir was studied. When the level of water naturally changes, the infection of crucians with Metorchis was found to be affected by their size, water temperature, and environmental pH values, and the human Opisthorchis affliction depends on the severity of infection of commercial-sized crucians by metacercariae. The infestation of the verkhovka was determined by the temperature of water and that of the lake minnow was by its size and the increased areas of the lake with the depths salubrious to its existence. With man-made effects (dewatering for watering agricultural lands) on the water regime of the reservoir, the infestation of the lake minnow depended on its size in the shallow water and on the level of water. Environmental factors, such as pH values, the area of shallow waters, and the size of mollusks, positively affected the higher extensiveness of infestation of mollusks with the parthenitae of opisthorchid flukes.

Agriculture↗

[Species affiliation of metacercaria of the genus Metorchis (Trematoda, Opisthorchidae) from fishes in Western Siberia].

Two larval species of the genus Metorchis, M. bilis and M. xanthosomus, are reported from fishes of West Siberia. Larvae of the first species can develop into adult forms in birds (terns, gulls, ducks) and in mammals (cats, golden hamsters, white mice). Larvae of the second species developed only in ducks. Experimental infection of golden hamsters, white mice and black terns with M. xanthosomus failed. On the results of the experimental infection and literary data the synonyms, M. bilis and M. xanthosomus, are given.

Animals↗

[The microstructure of trematodes studied by electron microscopy].

The main tendencies in the studies into the ultrastructure of trematodes (including species of medical importance) using scanning and transmission electron microscopy are considered. Attention was paid to disproportions in the studies into the different developmental stages of trematodes: maritae are better studied than parthenogenetic and larval stages and especially eggs and miracidia. During the last years the number of studies using the complex of histochemical, radioisotope and electron microscopic methods is increasing, among them the investigations on the changes caused by modern anthelmintic agents in the tegument and viscera of trematodes. These are mainly the trematodes of Schistosomatidae, Echinostomatidae, Fasciolidae and Paragonimidae families that were studied by electron microscopy, and the studies on Opisthorchidae are very scarce.

Animals↗

[Distomatosis: diagnosis and treatment].

Distomatosis caused by Fasciola hepatica is fairly common in France. It is due to the ingestion of contaminated watercress or wild dandelions. Fever is frequent. Jaundice and liver pain are inconstant. The disease is often revealed by an isolated eosinophilia. Ultrasonography and/or computerized tomography are useful to evaluate the hepatic lesions. The diagnosis is confirmed by the finding of eggs in the stools or by serological tests. Numerous other flukes may infect people living overseas and particularly in South-East Asia. Clonorchis sinensis and other Opisthorchidae are responsible for distomatosis of the liver and digestive tract. Several types of intestinal distomatosis may also be acquired. Paragonimiasis (a pulmonary fluke) is particularly frequent in that part of the world. The diagnosis rests on the finding of eggs in the stools (digestive tract distomatosis) or in the airways (paragonimiasis) or on serological tests. The prognosis has been improved by treatment with praziquantel, a drug which in most cases stops the development of the disease within a few days.

Animals↗

Assessment of stress-related bioindicators in winter flounder (Pleuronectes americanus) exposed to discharges from a pulp and paper mill in Newfoundland: a 5-year field study.

This study assessed the effects of discharges from a sulphite-bleaching paper mill on winter flounder (Pleuronectes americanus) sampled each spring over a 5-year period in St. George's Bay, Newfoundland, prior to foraging activity. The fish were captured by SCUBA divers near the mill and at a reference site 10 km up current. Several bioindicators were used to assess fish health. Larger and older flounder exhibiting gross and microscopic tissue lesions, lower condition factor, and elevated hepatosomatic index but lower gonadosomatic index that was associated with delayed development, were observed in samples caught near the mill compared to those at the reference site. Additionally, fish examined near the mill were infested with an ectoparasite, Cryptocotyle lingua, that causes black spot disease but harbored fewer numbers of a digene, Steringophorus furciger, in the digestive tract than samples taken at the reference site. These results suggest that abnormal size distribution, interruption of growth, high prevalence of lesions, lower condition factor, enlarged liver, delayed gonadal development, and differences in parasitic levels were indicative of stress in winter flounder caused by discharges from the mill compared to samples from a reference site. There was no evidence of a population decline in the inlet because of annual recruitment possibly from St. George's Bay into which it opens.

Animals↗

Molecular characterization and differentiation of opisthorchiid trematodes of the species Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1790) using polymerase chain reaction.

Adult specimens of the opisthorchiid liver fluke species Opisthorchis felineus and Metorchis bilis could be identified for the first time by molecular biological methods using species specific primers (OF and MB primers) in the polymerase chain reaction (PCR). The OF or MB primers were based on a part of the mitochondrial cytochrome c oxidase I gene. A specific product of approximately 200 bp could be amplified for O. felineus by means of the specific O. felineus primers. By contrast, the amplification of M. bilis DNA with MB primers produced a fragment of approximately 110 bp. A specificity of 100% could be demonstrated for both primer pairs. The sensitivities of the PCRs were 10 pg for the O. felineus DNA and 100 fg for the M. bilis DNA.

Animals↗

A sero-epidemiological survey on the occurrence of opisthorchiid liver flukes in red foxes ( Vulpes vulpes) in Berlin, Germany.

Serum samples collected from red foxes in the city of Berlin between 1996 and 1999 were analysed for the presence of antibodies against Opisthorchis felineus and Metorchis bilis using an indirect ELISA. Out of 1,000 specimens, 30.6% and 46.5% reacted positively with specific O. felineus and M. bilis antigens, respectively. Seroprevalence in adult foxes was always higher than in juveniles. While no significant differences were observed in adult foxes throughout the period, in juvenile specimens seroprevalence declined from 1996 to 1997, then stayed at a comparable level in 1998 and increased in 1999. A varying availability of fresh cyprinid fish in different years seems to be the reason for changes in seroprevalence. By grouping the samples from juvenile foxes by season, antibodies against both Metorchis and Opisthorchis antigens started to appear between April and June, increased between July and September()and reached a level comparable to adult foxes in the October to December quarter. The lowest seroprevalence was found in Pankow, which is the district with the lowest share of the surface water.

Animals↗

PCR diagnosis of infections with different species of Opisthorchiidae using a rapid clean-up procedure for stool samples and specific primers.

Infections with the opisthorchiid liver flukes Clonorchis sinensis, Opisthorchis viverrini, and Opisthorchis felineus cause serious health problems in endemic areas of Southeast Asia and countries of the former Soviet Union. Chronic infections--even with low worm burdens--may lead to the development of fatal cholangiocarcinoma and related symptoms. A more sensitive diagnosis is needed since the tiny eggs of the worms are often not seen in microscopic examinations of stool samples, especially in patients with low infections. This communication reports a rapid cleanup procedure for human stool samples, which enables reliable identification of DNA by polymerase chain reaction from few eggs of opisthorchiid flukes in fecal samples.

Animals↗

Kinase inhibition lengthens the period of the circadian pacemaker in the eye of Bulla gouldiana.

The inhibition of protein kinase activity by the isoquinoline sulfonamide, H-8, lengthens the period of the Bulla ocular circadian rhythm in a dose-dependent manner. In addition, the phosphorylation of 5 proteins is markedly affected by H-8. The observed correlation between H-8's period lengthening effects, and its effects on the phosphorylation of specific proteins, suggests that: (1) these proteins are candidate components regulating the period of the circadian rhythm; and (2) the daily changes in membrane potential underlying the circadian rhythm are mediated by similar mechanisms that serve to change neural function in other systems; modulation of protein kinases.

Animals↗

Common-source outbreak of acute infection due to the North American liver fluke Metorchis conjunctus.

BACKGROUND: We investigated an outbreak of acute clinical illness among 19 people who ate raw fish (sashimi) prepared from the white sucker, Catostomus commersoni, caught in a river north of Montreal, Canada. METHODS: We collected epidemiological, clinical, laboratory, and serological data on 19 individuals who ate the sashimi and six who did not. Because of the suggestive clinical picture, we set out to recover helminth parasites from uneaten fish. FINDINGS: The illness consisted of persistent upper abdominal pain, low grade fever, high blood eosinophil concentrations, and raised liver enzymes. After 10 days, opisthorchild-like eggs were found in stools. Symptoms persisted for 3 days to 4 weeks without treatment, but responded rapidly to praziquantel therapy. Necropsy of golden hamsters infected with metacercariae from uneaten fish revealed adult flukes identified as Metorchis conjunctus. INTERPRETATION: We describe an acute illness caused by the North American liver fluke M conjunctus. This is a new human disease and is the first report of a common-source outbreak of an acute illness caused by liver flukes of the family Opisthorchiidae.

Adult↗

Amphimerus bragai n. sp. (Digenea: Opisthorchiidae), a parasite of the rodent Nectomys squamipes (Cricetidae) from Minas Gerais, Brazil.

Amphimerus bragai n.sp. (Digenea, Opisthorchiidae) from the bile ducts of a rodent from the State of Minas Gerais, Brazil, Nectomys squamipes (Cricetidae), is described. The new species as studied by both light and scanning electron microscopy. A table is presented comparing the measurements of the new species with those of A. lancea (Diesing, 1850) and A. vallecaucensis Thatcher; 1970, parasites of dolphins and marsupials, respectively. The new species is similar in size and body form to A. vallecaucensis from which it differs in having a vitellarium that extends to the acetabulum while that of the former species are limited to the posterior one-third of the body. Additionally, the new species is from a rodent.

Animals↗

[Growth and development of Metorchis orientalis in chicks and its adult morphology].

In order to observe the infectivity, growth and development and adult morphology of Metorchis orientalis, a total of 40 chicks were experimentally infected with 100 metacercariae respectively, collected from Pseudorasbora parva. The worms of various developmental stages were recovered from chicks at 1.5, 3, 5, 7, 9, 11, 14 and 21 days after infection, and they were prepared for morphological observations and measurements. All of the worms were found in the gallbladders of chicks, and their recovery rate was 32% in average. The growth of the body was rapid from 9 to 11 days after infection. The genital primordia appeared in 1.5 and 3-day old worms, and ovary and testes were first observed in 5-day old worms. Thereafter, genital organs gradually matured and completed up to 11 days after infection. The adult worm was leaf-like, and possessed a convoluted tubular seminal vesicle, an ovoid ovary, a sac-like seminal receptacle, 2 lobed-testes and follicular vitellaria. Eggs were 31.9 x 15.3 microns in average size, ellipsoid to elliptical in shape and possessed abopercular thickenings. From the above results, it is concluded that M. orientalis grows in sigmoid pattern in chicks, and their genital organs fully mature between days 9 and 11. It is also confirmed that a chick is a new definitive host of M. orientalis.

Animals↗

Trematodes of the family Opisthorchiidae: a minireview.

Examination of the original descriptions of genera placed within the family Opisthorchiidae has revealed that only 33 of the original 43 genera are valid members of this family. Further study of these descriptions should also reveal that many of the subfamilies are also invalid. With reference to the original descriptions of these genera, and subsequent literature, a brief survey of the family has been compiled. Information on the spectrum of definitive hosts that these helminths parasitize is provided, as well as information on the life cycles, geographic distribution, and socioeconomic impacts of the family. More in-depth information is given on those species that are of particular medical importance; namely, Clonorchis sinensis, Opisthorchis viverrini, and O. felineus. The final aims of this review are to provide information on the entire genera of the family Opisthorchiidae, which will aid understanding of the phylogenetic relationships not only within the family, but also within the Class Trematoda.

Animals↗