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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Antigenic preparations from Opisthorchis and their use in immunodiagnosis. 1. The specificity of antigenic preparations from Opisthorchis].

Immunochemical tests of various antigenic preparations derived from Opisthorchis revealed specific components in metabolic, somatic and ovular specimens. Furthermore, the study revealed a common somatic antigenic components in Opisthorchis, Echinococcus and Fasciola. The specificity revealed makes the implementation of Opisthorchis immunoreagents advisable for the diagnosis of opisthorchiasis.

Animals↗
PubMed2006

Comparison of gene expression profiles between Opisthorchis viverrini and non-Opisthorchis viverrini associated human intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary cancer in the liver, and its incidence is highest in the northeastern part of Thailand. ICCs in this region are known to be associated with infection with liver flukes, particularly Opisthorchis viverrini (OV), as well as nitrosamines from food. To clarify molecular mechanisms of ICC associated with or without liver flukes, we analyzed gene expression profiles of OV-associated ICCs from 20 Thai patients and compared their profiles with those of 20 Japanese ICCs that were not associated with OV, by means of laser microbeam microdissection and a cDNA microarray containing 27,648 genes. We identified 77 commonly upregulated genes and 325 commonly downregulated genes in the two ICC groups. Unsupervised hierarchical cluster analysis separated the 40 ICCs into two major branches almost completely according to the fluke status. The putative signature of OV-associated ICC exhibited elevated expression of genes involved in xenobiotic metabolism (UGT2B11, UGT1A10, CHST4, SULT1C1), whereas that of non-OV-associated ICC represented enhanced expression of genes related to growth factor signaling (TGFBI, PGF, IGFBP1, IGFBP3). Additional random permutation tests identified a total of 49 genes whose expression levels were significantly different between the two groups. We also identified genes associated with macroscopic type of ICCs. In conclusion, these data may not only contribute to clarification of common and OV-specific mechanisms underlying ICC, but also may serve as a starting point for the identification of novel diagnostic markers or therapeutic targets for the disease.

Adult↗
PubMed2001

Prevalence of Opisthorchis viverrini infection among villagers harboring Opisthorchis-like eggs.

The precise occurrence of Opisthochis viverrini infection in humans, who were positive for Opisthorchis-like eggs in a stool examination, was determined using the potassium permanganate staining method. In the 68 specimens examined, there were more individual O. viverrini eggs (38.24%) than singular Haplorchis taichui eggs (29.41%). One-fourth of the total specimens contained a mixed infection of O. viverrini and H. taichi eggs. The median ratio of O. viverrini: H. taichui eggs in mixed infection cases was 2.29 (min = 1, max = 17.5). It is suggested that chemotherapy with praziquentel treatment should be given to patients who are positive for O. viverrini-like eggs.

Animals↗
PubMedDate not supplied

[Fish infection with Opisthorchis larvae in Russia and some contiguous countries (by the materials of the "Cadaster of opisthorchis infection foci in Russia in 1994"].

A cadastre of opisthorchiasis foci with places under study and specious fish invasion with larvae of this helminthiasis has been first drawn up. Opisthorchis larvae have been found to be recorded in 23 species and 2 subspecies of the Cyprinidae family and 1 species of the Cobitidae family. The cadastre permits the areas epidemiologically hazardous due to opisthorchiasis to be determined. The data on fish species-specific infection in different river basins may render a great deal of aid to sanitary-and-epidemiological surveillance workers in implementing preventive measures in specific regions.

Animals↗
PubMed1991

Opisthorchis viverrini: relationships between egg counts, worms recovered and antibody levels within an endemic community in northeast Thailand.

Three techniques for estimating the intensity of Opisthorchis viverrini infection in individuals from a Northeast Thai community are compared. Egg counts were determined using a quantitative formalin/ethyl acetate technique, worm burdens were estimated by expulsion chemotherapy and antibody levels were measured by ELISA. Log-transformed worm and egg counts were closely correlated (r = 0.80), suggesting that both measurements provide good assessments of relative intensity of infection. However, no Opisthorchis worms were recovered from 34 people with high egg counts; probably due to problems with the expulsion technique in some individuals. Examination of egg production per fluke indicated that each fluke contributed an average of 180 eggs per gram (epg) of faeces and fecundity was negatively associated with total worm burden. Serum IgG levels correlated significantly with Opisthorchis egg count (r = 0.61) at two independent assessments. Although significant associations were observed between antibody levels and echinostome infection, analysis suggested that these reflected independent associations between these two variables and Opisthorchis infection and age. We conclude that all three measurements are useful for epidemiological studies.

Animals↗
PubMed2003

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↗
PubMedDate not supplied

[The differentiation of Opisthorchis eggs by the ultrastructure of their outer membranes].

Using a TESLA-BS-300 scanning electron microscope, the ultrastructure of the outer membranes of oocysts of 8 opisthorchis species (Opisthorchis felineus, O. viverrini, O. geminus, Clonorchis sinesis, Amphimerus anatis, Metorchis albidus, Pseudamphistomum truncatum, Erchoviorchis lintoni) belonging to 4 subfamilies, as well as that of O. felineus oocysts of various geographical isolates (from the Ukraine, the Volga region, West Siberia, Kazakhstan) have been investigated. The nature of the ultrastructure of the membranes differs from species to species and can be used for the differentiation of opisthorchis oocysts. Marked differences have been observed in different opisthorchis subfamilies (Opisthorchinae, Metorchinae, Pseudamphistominae, Pseudamphimerinae). The membrane ultrastructure was not significantly different in O. felineus oocysts from various geographical isolates, however, there are some distinctions in the size of oocysts and the form of apical thorns and opercular endings. The work has been done within the framework of the international scientific cooperation between the E. I. Martsinovskiĭ Institute of Medical Parasitology and Tropical Medicine, USSR Ministry of Public Health and the Institute of Parasitology, the Czechoslovakian Academy of Sciences.

Animals↗
PubMed1983

Ultrastructural investigations on the effects of praziquantel on human trematodes from Asia: Clonorchis sinensis, Metagonimus yokogawai, Opisthorchis viverrini, Paragonimus westermani and Schistosoma japonicum.

The effect of praziquantel (Biltricide) on the ultrastructure of trematodes pathogenic to man in Asia was investigated in: Clonorchis sinensis, Opisthorchis viverrini, Schistosoma japonicum, Metagonimus yokogawai, and Paragonimus westermani. The different parasites were isolated from their respective experimental hosts and uniformly incubated for 5, 15, 30 or 60 min at 37 degrees C in medium TC 199 containing 0, 1, 10 or 100 micrograms praziquantel/ml. All parasites exposed to praziquantel were contracted and displayed tegumental alterations. 1. Clonorchis sinensis, Opisthorchis viverrini and Schistosoma japonicum reacted with severe tegumental vacuolisation within 5 min after exposure to 1 microgram praziquantel/ml. The extent of the damage induced increased with exposure time. 2. In vivo treated Opisthorchis viverrini worms had the same damages as in vitro treated ones. 3. Metagonimus yokogawai displayed the same degree of vacuolisation after exposure to all concentrations of praziquantel. Complete destruction of the tegumental surface was not achieved, however, possibly because of the presence of numerous tegumental hooks. 4. Paragonimus westermani was least sensitive to praziquantel. Only very few vacuoles were formed after incubation in 100 micrograms/ml for 60 min. It is assumed that the very dense texture of the thick tegument is responsible for the relative refractoriness to praziquantel in vitro. However, in vivo the parasite is successfully eliminated by praziquantel.

Animals↗
PubMed1993

Ultrastructural hepatic alterations in hamsters and jirds after experimental infection with the liver fluke Opisthorchis viverrini.

Changes in the hepatocytes of male hamsters (Mesocricetus auratus) and jirds (Meriones unguiculatus) at 220 days after experimental infection with the liver fluke Opisthorchis viverrini were studied by light and electron microscopy. The hepatocytes of the control group were characterized by an intracellular compartmentation. A globular nucleus was located centrally. The main features of the perinuclear zone were the cisternae of the rough endoplasmic reticulum (RER) and interjacent mitochondria, lysosomes, and peroxisomes. The peripheral cell region was dominated by glycogen fields and scattered lipid droplets, which were surrounded by anastomosing tubules of the smooth endoplasmic reticulum (SER). An immense proliferation of the SER was striking in the hepatocytes of animals infected with O. viverrini. Coincidentally, the intracellular compartmentation disappeared. Glycogen rosettes, RER, lysosomes, and lipid droplets were distributed irregularly all over the cell, the latter being observed more frequently than in control animals. The nuclei showed lobe-like protrusions and were enlarged. The mitochondria were often dumbbell-shaped and showed pathologic degenerations up to lysis. Our results resemble those of numerous investigations concerning hepatocellular alterations caused by N-nitroso compounds. Therefore, these observations suggest a synergistic effect for trematode infection and N-nitroso compounds in the pathogenesis of opisthorchiasis. The cellular alterations observed in the hepatocytes of Opisthorchis-infected animals together with the accumulation of intermediate filaments seen in the adjacent bile-duct epithelia and in the epithelium of the gall-bladder seem to indicate a disturbance of the cell metabolism and might be related to a neoplastic transformation.

Animals↗
PubMed1992

Detection of Opisthorchis viverrini antigens in stools using specific monoclonal antibody.

Detection of Opisthorchis viverrini antigens in stools using specific monoclonal antibody. International Journal for Parasitology 22: 527-531. A sandwich enzyme-linked immunosorbent assay (ELISA) was developed for detecting Opisthorchis viverrini antigen in faecal extracts of four groups of individuals. These were 24 patients with O. viverrini infection only (group 1), 31 patients with O. viverrini and other parasitic infections (group 2), 141 patients with other parasitic infections (group 3) and 21 normal, parasite-free individuals (group 4). The first antibody used in the ELISA was polyclonal immunoglobulin G prepared from the serum of a rabbit previously immunized with crude extract of O. viverrini. The second antibody was monoclonal antibody specific to an antigen located in the worm tegument and muscular tissue. Sensitivity of the assay was 31% while specificity was 100%. Considerations for improving the sensitivity are discussed.

Animals↗
PubMed2003

Immunology and molecular biology of Opisthorchis viverrini infection.

Opisthorchiasis is the major public health problems in Laos PDR and Thailand. The disease becomes chronic and persists for many years, leading to hepatobiliary disease and cholangiocarcinoma. Less severe manifestations include cholangitis, chronic cholecystitis and cholelithiasis. A significant degree of humoral and cell mediated immune responses to the parasite can be detected both in patients and animal models. The patients IgG levels appear to correlate with gall bladder size and dysfunction and correlated significantly with opisthorchis egg count and decrease after treatment. However, the possible significance of these immune responses to protective immunity is presently unknown. The development of immunodiagnostic method for Opisthorchis viverrini detection has been attempted. The components with molecular weight >116, 89, 78 and 20 kDa appear to be specifically associated with the somatic extract of adult fluke. The 89 kDa protein is the most prominent component found in the in vitro culture fluid of adult worms and the metacercarial extract that can be a candidate with significant immunodiagnostic potential. Highly specific and sensitive monoclonal antibodies for O. viverrini antigens were prepared to detect parasite antigens in stool and antibody in serum. Information regarding the molecular approaches of O. viverrini is very limited. The genome of O. viverrini has neither CpG nor A methylated as found in other parasites. The total length O. viverrini ribosomal DNA is approximately 13 kb. and the presence of a highly repeated DNA specific for the parasite was demonstrated. A O. viverrini specific DNA probe was constructed and PCR based detection with high specificity for amplification of the repeated sequences is performed to detect the presence of eggs' DNA in stool samples in comparison with classical methods.

Animals↗
PubMed1990

Immunological analysis of Opisthorchis and Clonorchis antigens.

Immunoreactive components of Opisthorchis viverrini and Clonorchis sinensis were analysed by enzyme-linked immunosorbent assay (ELISA), radioimmunoprecipitation and immunoblotting. Somatic extracts from these two liver flukes as well as from other related parasites, together with the metabolic products, were tested for their reactivities with sera from patients with opisthorchiasis and clonorchiasis. A significant cross-reactivity in the ELISA was noted between Opisthorchis and Clonorchis. Immunoblotting and radioimmunoprecipitation analyses showed that the 89-kD protein which was previously shown to be a predominant metabolic product of O. viverrini reacted with sera from both groups of patients. However, an antigen with a molecular weight of 16 kD, apparently a predominant somatic component, appeared to be specific for O. viverrini.

Animals↗
PubMed1991

Distribution patterns of Opisthorchis viverrini within a human community.

This paper describes patterns of infection with Opisthorchis viverrini within a human community assessed by egg count, parasite-specific antibody levels and worm burden determined by expulsion chemotherapy. All three measurements increased significantly with age, reaching a plateau in young adults. There were no significant sex-associated differences in the prevalence or intensity of infection, antibody levels, or in the frequency of heavy worm burdens. A striking 81.5% of the total Opisthorchis population and 74% of the total egg output were expelled by the most heavily infected 10% of the humans sampled. This extreme over-dispersion, together with recent findings that hepatobiliary disease frequently accompanies heavy infections, argues that the priority for community-based parasite control programmes should be to maximize treatment and health promotion efforts toward heavily infected individuals.

Adolescent↗
PubMed1999

Potassium permanganate staining for differentiation the surface morphology of Opisthorchis viverrini, Haplorchis taichui and Phaneropsolus bonnei eggs.

Potassium permanganate staining method was developed for differentiation Opisthorchis viverrini, Haplorchis taichui and Phaneropsolus bonnei eggs. The surfaces of O. viverrini, H. taichui and P. bonnei eggs stained permanently and temporarily were similar in appearance even the staining procedures were varied both in concentration and time. Determined under light microscope set at 400x, all of these eggs were oval-shaped, operculated at one pole and indistinct small knob at posterior end. O. viverrini eggs showed the distinct musk-melon-like prominent ridges on the surface. Haplorchis taichui eggs had a light striae pattern while P. bonnei eggs had a smooth egg shell. Length of these trematode eggs were significant different (chi2 test, p < 0.05). Mean +/- SD of O. viverrini, H. taichui and P. bonnei eggs were 26.34 +/- 1.65 microm, 29.03 +/- 1.48 microm and 23.00 +/- 1.49 microm, respectively. Regarding of their width, the mean +/- SD of O. viverrini, H. taichui and P. bonnei eggs were 15.54 +/- 0.69 microm. 14.94 +/- 0.91 microm and 12.25 +/- 1.02 microm, respectively. The means of width of O. viverrini and H. taichui eggs were not significantly different (chi2 test, p > 0.05), however, they were significantly different from those of P. bonnei (chi2 test, p < 0.05). Temporary staining using 1% w/v concentration and only 1 minute of time is useful in the mass fecal examination survey for the prevalence and intensity of truly Opisthorchis infection.

Animals↗
PubMed2000

An epidemiological study on Opisthorchis viverrini infection in Lao villages.

The prevalence of liver fluke, Opisthorchis viverrini, infection in rural and urban communities was studied in Khammouane Province in Lao PDR. The infection was the commonest among the villagers examined, showing the positive rates of 52.9% and 55.0% in two rural communities and 60.7% in an urban community, respectively. The infection rate reached up to 20% or more within 4 years after birth and increased with age to a plateau in the age group over 20 years. The highest prevalence rate was over 80% in the age group of 35-54 years. The age-related patterns of infection in males and females were almost the same, although there were some sex-related differences by village and by age group. Infection with Opisthorchis viverrini appears to be a serious public health problem strongly associated with the frequent eating habit of raw fish in low land Laos.

Adolescent↗