Modeling the persistence of Opisthorchis viverrini worm burden after mass-drug administration and education campaigns with systematic adherence

Opisthorchis viverrini is a parasitic liver fluke contracted by consumption of raw fish, which affects over 10 million people in Southeast Asia despite sustained control efforts. Chronic infections are a risk factor for the often fatal bile duct cancer, cholangiocarcinoma. Previous modeling predicted rapid elimination of O. viverrini following yearly mass drug administration (MDA) campaigns. However, field data collected in affected populations shows persistence of infection, including heavy worm burden, after many years of repeated interventions. A plausible explanation for this observation is systematic adherence of individuals in health campaigns, such as MDA and education, with some individuals consistently missing treatment. We developed an agent-based model of O. viverrini which allows us to introduce various heterogeneities including systematic adherence to MDA and education campaigns at the individual level. We validate the agent-based model by comparing it to a previously published population-based model. We estimate the degree of systematic adherence to MDA and education campaigns indirectly, using epidemiological data collected in Lao PDR before and after 5 years of repeated MDA, education and sanitation improvement campaigns. We predict the impact of interventions deployed singly and in combination, with and without the estimated systematic adherence. We show how systematic adherence can substantially increase the time required to achieve reductions in worm burden. However, we predict that yearly MDA campaigns alone can result in a strong reduction of moderate and heavy worm burden, even under systematic adherence. We predict latrines and education campaigns to be particularly important for the reduction in overall prevalence, and therefore, ultimately, elimination. Our findings show how systematic adherence can explain the observed persistence of worm burden; while emphasizing the benefit of interventions for the entire population, even under systematic adherence. At the same time, the results highlight the substantial opportunity to further reduce worm burden if patterns of systematic adherence can be overcome.

Influence of misconceptions and inappropriate eating behaviors on Opisthorchis viverrini infection among at-risk populations undergoing cholangiocarcinoma screening in Northeastern Thailand

Raw or undercooked freshwater fish consumption contributes to persistent Opisthorchis viverrini infection in Northeast Thailand. This study aims to assess the relationship between misconceptions, unhealthy eating habits, and O. viverrini infection. Data were obtained from the Cholangiocarcinoma Screening and Care Program in Northeast Thailand from 2019 to 2021. Participants were screened for O. viverrini annually over the following 2 years using the Kato-Katz technique. Misconceptions and unhealthy eating habits were assessed through questionnaires. The relationship between these factors and O. viverrini infection was evaluated using adjusted risk ratios (ARRs) and 95% confidence intervals (CIs) from generalized estimating equations under binomial regression framework. Of 5375 participants screened for O. viverrini over 3 years, infection rates were 21.53%, 10.7%, and 4.6% each year, respectively. Out of those, 636 participants responded to questions regarding misconceptions. Results showed that participants who believed in the efficacy of putting lime or red ants in Koi pla (raw fish salad) or eating Koi pla with white whiskey to kill parasites, and early-stage cholangiocarcinoma can be cured, were 41% (ARR, 1.41; 95% CI, 1.03-1.94) and 57% (ARR, 1.57; 95% CI, 1.06-2.33), respectively, more likely to be infected with O. viverrini. Our study confirms that belief in using lime or red ants in Koi pla or eating Koi pla with white whiskey to make it cooked, or early-stage cholangiocarcinoma can be cured, increases O. viverrini infection risk in high-risk populations. Changing health beliefs and eating habits is necessary to reduce O. viverrini infection and its risk to cholangiocarcinoma.

Inflammatory cell responses in biliary mucosa during Opisthorchis viverrini infection: Insights into susceptibility differences among hosts

Background

Individual host susceptibility is believed to be a risk factor in the interaction between the host and the parasite. Since studying time series in humans is limited, animal models are replaced.

Aim

This study aims to explore and compare the pattern of inflammatory cell types along the biliary tract and their association with proliferative lesions in the early development of cholangiocarcinoma from susceptible and nonsusceptible animal models.

Methods

Thirty male Syrian golden hamsters and 30 BALB/c mice, serving as the susceptible and nonsusceptible animal models, were used in this comparative study. The animals were infected with 50 Opisthorchis viverrini metacercariae via gastric intubation. At days 1, 2, 7, 14, 28, and 56 postinfection (p.i.), five animals were randomly selected from each group and humanely sacrificed. The hepatobiliary tissues were collected and processed for histopathological study. Histochemical and immunohistochemical staining were applied to differentiate the inflammatory cell types. Kruskal-Wallis and Mann-Whitney tests were applied to assess all semi-quantitative and quantitative variables. The correlation between each variable was also analyzed using Spearman rank at a p-value < 0.05.

Results

The results demonstrated that mice had different patterns of infiltrating cell types when compared to hamsters. This suggested that the cellular response to the infection in mice occurred earlier than that in hamsters. The response in mice reached its peak at D7 to D14 and then rapidly declined at D28. In contrast, although the inflammatory response in hamsters started slowly, the response reached the peak at D28 and maintained a high level until D56. Significant differences in the number of inflammatory cells between mice and hamsters were seen at D1 (p = 0.047), D7 (p = 0.049), D28 (p = 0.040), and D56 (p < 0.040).

Conclusion

The inflammatory responses to O. viverrini infection in the nonsusceptible animal model occurred and declined earlier while the response in the susceptible animal model occurred later in a gradual manner. Both rodents are suitable animal models for the studies of opisthorchiasis susceptibility.

Distinct antibody response in susceptible and non-susceptible hosts of the carcinogenic liver fluke Opisthorchis viverrini infection

Opisthorchis viverrini is a carcinogenic parasite that can cause bile duct cancer called cholangiocarcinoma. A study of the immune response of this parasite in susceptible and non-susceptible hosts may provide a clue to develop vaccines and immunodiagnostic markers, which are currently not available. Here, we compared the antibody response in susceptible Golden Syrian hamsters and non-susceptible BALB/c mice infected by the liver fluke. In mice, the antibody was detected between 1 and 2 weeks post-infection, whereas it was positive between 2 and 4 weeks post-infection in hamsters. Immunolocalization revealed that the antibody from mice reacts strongly with the tegumental surface and gut epithelium of the worm, while hamster antibody showed a weak signal in the tegument and a comparable signal in the gut of the worm. Immunoblot of the tegumental proteins demonstrated that while hamster antibody showed a broad specificity, mice strongly reacted with a single protein band. Mass spectrometry revealed these immunogenic targets. Recombinant proteins of the reactive targets were produced in the bacterial expression system. The immunoblot of these recombinant proteins confirm the reactivity of their native form. In summary, there is a different antibody response against O. viverrini infection in susceptible and non-susceptible hosts. The non-susceptible host reacts quicker and stronger than the susceptible host.

Knockout of liver fluke granulin, Ov-grn-1, impedes malignant transformation during chronic infection with Opisthorchis viverrini

Infection with the food-borne liver fluke Opisthorchis viverrini is the principal risk factor for cholangiocarcinoma (CCA) in the Mekong Basin countries of Thailand, Lao PDR, Vietnam, Myanmar and Cambodia. Using a novel model of CCA, involving infection with gene-edited liver flukes in the hamster during concurrent exposure to dietary nitrosamine, we explored the role of the fluke granulin-like growth factor Ov-GRN-1 in malignancy. We derived RNA-guided gene knockout flukes (ΔOv-grn-1) using CRISPR/Cas9/gRNA materials delivered by electroporation. Genome sequencing confirmed programmed Cas9-catalyzed mutations of the targeted genes, which was accompanied by rapid depletion of transcripts and the proteins they encode. Gene-edited parasites colonized the biliary tract of hamsters and developed into adult flukes. However, less hepatobiliary tract disease manifested during chronic infection with ΔOv-grn-1 worms in comparison to hamsters infected with control gene-edited and mock-edited parasites. Specifically, immuno- and colorimetric-histochemical analysis of livers revealed markedly less periductal fibrosis surrounding the flukes and less fibrosis globally within the hepatobiliary tract during infection with ΔOv-grn-1 genotype worms, minimal biliary epithelial cell proliferation, and significantly fewer mutations of TP53 in biliary epithelial cells. Moreover, fewer hamsters developed high-grade CCA compared to controls. The clinically relevant, pathophysiological phenotype of the hepatobiliary tract confirmed a role for this secreted growth factor in malignancy and morbidity during opisthorchiasis.

Cholangiocarcinoma protective factors in Greater Mekong Subregion: Critical issues for joint planning to sustainably solve regional public health problems

Although Opisthorchis viverrini (OV), lifestyle, and diet co-factors have a relatively high prevalence in the Greater Mekong Subregion (GMS) population, cumulative (0–74) incidence rates of cholangiocarcinoma (CCA) do not reach 5% in this region. Other co-factors must influence, but in this study, we only highlighted positive factors for guiding joint planning to address public health problems at the regional level. Therefore, we aimed to study prevalence and factors associated with CCA incidence focusing only on protective factors. A cross-sectional analytic study was carried out from June to October 2017. Participants with informed consent completed the questionnaires. Descriptive statistics were used to analyze general information. Primary variables were classified into high and low levels by mean. Logistic regression was employed to investigate the correlation between interesting variables and the overall risk level of CCA. The overall prevalence of CCA protective factors of the whole region was knowledge (61.39%), health beliefs (42.32%), prevention behavior (31.93%), and community participation (14.53%). When considering the proportions at a high level, they were 49.53%, 53.72%, 35.37%, and 49.67%, respectively. Significant factors associated with CCA prevention were females with secondary or vocational education, a high level of perceived seriousness and benefits, and community participation. These findings are likely to be helpful for both the public and administrators. First, it can be information for people to be aware of CCA risk. Second, policy-driven authorities at the local or regional level should apply the critical issues from this study for joint planning to sustainably solve regional public health problems.

Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit beta as a potential biomarker for Opisthorchis viverrini infection and cholangiocarcinoma

The human liver fluke Opisthorchis viverrini (Ov), the primary risk factor for cholangiocarcinoma (CHCA), is a parasite endemic to southeast Asian countries. With no effective treatments for CHCA currently available, early diagnosis and treatment of Ov infection remains the only practical method for the prevention of CHCA. In this study, plasma phosphoproteomes of patients in the non-Ov infection, non-cholangiocarcinoma subject group (non-OVCCA), the asymptomatic Ov infected group (OV), and the CHCA group (CCA), were investigated to identify potential biomarkers for Ov infection and CHCA. The AKT signalling pathway was found to be up-regulated. Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit beta isoform (PIK3CB), an upstream signalling molecule, was selected as a potential biomarker and evaluated using indirect enzyme-linked immunosorbent assay (ELISA). Results demonstrated evidence that levels of PIK3CB in both the OV group and CCA group was statistically different compared to the non-OVCCA group (P < 0.01). However, the levels of PIK3CB between the OV group and the CCA group were found not to be statistically different. Sensitivity and specificity for OV using OD450 cut-off at >1.570 was 76 and 72%, respectively. For CCA, sensitivity and specificity using OD450 cut-off at >1.398 was 68 and 76%, respectively. Application of indirect ELISA detecting plasma PIK3CB will be of great benefit for screening of opisthorchiasis and CHCA.

Recombinant Opisthorchis viverrini tetraspanin expressed in Pichia pastoris as a potential vaccine candidate for opisthorchiasis

Opisthorchiasis affects millions of people in Southeast Asia and has been strongly associated with bile duct cancer. Current strategic control approaches such as chemotherapy and health education are not sustainable, and a prophylactic vaccine would be a major advance in the prevention of the disease. Tetraspanins are transmembrane proteins previously described as potential vaccine candidates for other helminth infections and are also found in the membranes of the tegument and extracellular vesicles of O. viverrini. Here, we investigated the potential of a recombinant protein encoding for the large extracellular loop of O. viverrini tetraspanin-2 (rOv-LEL-TSP-2) in a hamster vaccination model. Hamsters were vaccinated with 50 and 100 μg of rOv-LEL-TSP-2 produced from Pichia pastoris yeast combined with alum CpG adjuvant via the intraperitoneal route. The number of worms recovered from hamsters vaccinated with rOv-LEL-TSP-2 was significantly reduced compared to adjuvant control groups. Fecal egg output was also significantly reduced in vaccinated animals, and the average length of worms recovered from vaccinated animals was significantly shorter than that of the control group. Vaccinated animals showed significantly increased levels of anti-rOv-TSP-2 IgG in the sera after three immunizations, as well as increased levels of several T helper type 1 cytokines in the spleen including IFN-γ and IL-6 but not the Th2/regulatory cytokines IL-4 or IL-10. These results suggest that rOv-TSP-2 could be a potential vaccine against opisthorchiasis and warrants further exploration.

Bovine fasciolisis in São Paulo state, Brazil

Fasciolosis is a zoonotic disease with a worldwide distribution caused by Fasciola hepatica, which leads to severe economic losses in cattle such as reducing meat and milk production, livers condemnation, growth retardation and increase in mortality. From October 2008 to April 2011, condemned bovine livers in slaughterhouses of different municipalities from São Paulo state, Brazil were evaluated for the presence of Fasciola hepatica. Out of 20,635 analyzed livers, 1422 were infected with F. hepatica. These cattle came from 33 municipalities, out of which 16 showed infected animals and where 7 municipalities did not show statistical difference between each month throughout the year: Tuiuti - 276/1408 (19,6%), Atibaia - 44/257 (17,1%), Joanópolis - 116/738 (15,7%), Bragança Paulista - 318/2316 (13,3%), Piracaia - 182/1442 (12,6%), Santo Antonio de Posse - 118/1005 (11,7%), Amparo 131/2003 (6,5%). The other nine municipalities, Monte Alegre do Sul, Descalvado, Campinas, Morungaba, Pedreira, Socorro, Munhoz, Jaguariúna and Itatiba showed a positive percentage varying from 5.08% to 1.46%. Our results demonstrated the presence of F. hepatica in this region was higher than official data, bringing the need for control measures. There is also an apparent increase in fasciolosis two to three months after low to medium precipitation, however high precipitation causes a decrease in fasciolosis prevalence.

Newly Described Coccidia Goussia bayae from White Perch Morone americana: Morphology and Phylogenetics Support Emerging Taxonomy of Goussia within Piscine Hosts

In March and April 2016, 150 white perch ( Morone americana) were collected from various localities in Chesapeake Bay and examined for coccidia. A previously undescribed species of coccidia was observed in the hepatic bile ducts and gallbladder of all white perch (100%) examined. We describe this species using morphological characteristics, histology, and gene sequences of the small-subunit ribosomal DNA ( rDNA), large-subunit rDNA, and mitochondrial genes cytochrome oxidase 1 ( COI), cytochrome oxidase b ( Cytb), and cytochrome oxidase 3 ( COIII). Oocysts of Goussia bayae n. sp. were subspherical with a single-layered smooth wall and measured (length [L] × width [W]) 26.2 × 21.8 μm, with a L/W ratio of 1.2. A micropyle was present but a micropyle cap, polar granules, and oocyst residuum were absent. Each oocyst contained 4 sporocysts that were ellipsoidal and measured (L × W) 12.6 × 7.8 μm, with a L/W ratio of 1.6. A pair of sporozoites was present, but sporocysts lacked a Stieda body and residuua. Meronts and gamonts were epicellular in biliary epithelial cells and oocysts were coelozoic in hepatic and common bile ducts and gallbladder. This is the first report of Goussia spp. from white perch and the first mitochondrial DNA sequence reported from a Goussia species. Phylogenetic analysis indicates basal placement of G. bayae to Eimeriidae, Choleoeimeria, and Sarcocystidae.

Programmed knockout mutation of liver fluke granulin attenuates virulence of infection-induced hepatobiliary morbidity

Infection with the food-borne liver fluke Opisthorchis viverrini is the principal risk factor (IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2012) for cholangiocarcinoma (CCA) in the Lower Mekong River Basin countries including Thailand, Lao PDR, Vietnam and Cambodia. We exploited this link to explore the role of the secreted growth factor termed liver fluke granulin (Ov-GRN-1) in pre-malignant lesions by undertaking programmed CRISPR/Cas9 knockout of the Ov-GRN-1 gene from the liver fluke genome. Deep sequencing of amplicon libraries from genomic DNA of gene-edited parasites revealed Cas9-catalyzed mutations within Ov-GRN-1. Gene editing resulted in rapid depletion of Ov-GRN-1 transcripts and the encoded Ov-GRN-1 protein. Gene-edited parasites colonized the biliary tract of hamsters and developed into adult flukes, but the infection resulted in reduced pathology as evidenced by attenuated biliary hyperplasia and fibrosis. Not only does this report pioneer programmed gene-editing in parasitic flatworms, but also the striking, clinically-relevant pathophysiological phenotype confirms the role for Ov-GRN-1 in virulence morbidity during opisthorchiasis.

TLR2 signal influences the iNOS/NO responses and worm development in C57BL/6J mice infected with Clonorchis sinensis

BACKGROUND

Although the responses of inducible nitric oxide synthase (iNOS) and associated cytokine after Clonorchis sinensis infection have been studied recently, their mechanisms remain incompletely understood. In this study, we investigated the effects of toll-like receptor 2 (TLR2) signals on iNOS/nitric oxide (NO) responses after C. sinensis infection. We also evaluated the correlations between iNOS responses and worm development, which are possibly regulated by TLR2 signal.

METHODS

TLR2 wild-type and mutant C57BL/6 J mice were infected with 60 C. sinensis metacercariae, and the samples were collected at 30, 60, 90 and 120 days post-infection (dpi). The total serum NO levels were detected using Griess reagent after nitrate was reduced to nitrite. Hepatic tissue samples from the infected mice were sliced and stained with hematoxylin and eosin (HE) to observe worm development in the intrahepatic bile ducts. The iNOS mRNA transcripts in the splenocytes were examined by real time reverse transcriptase polymerase chain reaction (qRT-PCR), and iNOS expression was detected by immunohistochemistry.

RESULTS

Developing C. sinensis juvenile worms were more abundant in the intrahepatic bile ducts of TLR2 mutant mice than those of TLR2 wild-type mice. However, no eggs were found in the faeces of both mice samples. The serum levels of total NO significantly increased in TLR2 mutant mice infected with C. sinensis at 30 (t (5) = 2.595, P = 0.049), 60 (t (5) = 7.838, P = 0.001) and 90 dpi (t (5) = 3.032, P = 0.029). Meanwhile, no changes occurred in TLR2 wild-type mice compared with uninfected controls during the experiment. The iNOS expression in splenocytes showed unexpected higher background levels in TLR2 mutant mice than those in TLR2 wild-type mice. Furthermore, the iNOS mRNA transcripts in splenocytes were significantly increased in the TLR2 wild-type mice infected with C. sinensis at 30 (t (5) = 5.139, P = 0.004), 60 (t (5) = 6.138, P = 0.002) and 90 dpi (t (5) = 6.332, P = 0.001). However, the rising of iNOS transcripts dropped under the uninfected control level in the TLR2 mutant mice at 120 dpi (t (5) = -9.082, P < 0.0001). Both total NO and iNOS transcripts were significantly higher in the TLR2 mutant mice than those in the TLR2 wild-type mice at 30 (t (5) = 3.091/2.933, P = 0.027/0.033) and 60 dpi (t (5) = 2.667/6.331, P = 0.044/0.001), respectively. In addition, the remarkable increase of iNOS expressions was immunohistochemically detected in the splenic serial sections of TLR2 wild-type mice at 30 and 60 dpi. However, the expressions of iNOS were remarkably decreased in the splenocytes of both TLR2 wild-type and mutant mice at 120 dpi.

CONCLUSIONS

These results demonstrate that TLR2 signal plays an important role in the regulation of iNOS expression after C. sinensis infection. TLR2 signal is also beneficial to limiting worm growth and development and contributing to the susceptibility to C. sinensis in which the iNOS/NO reactions possibly participate.

Peroxiredoxin 6 expression is inversely correlated with nuclear factor-κB activation during Clonorchis sinensis infestation

Clonorchis sinensis is a carcinogenic human liver fluke. Its infection promotes persistent oxidative stress and chronic inflammation environments in the bile duct and surrounding liver tissues owing to direct contact with worms and their excretory-secretory products (ESPs), provoking epithelial hyperplasia, periductal fibrosis, and cholangiocarcinogenesis. We examined the reciprocal regulation of two ESP-induced redox-active proteins, NF-κB and peroxiredoxin 6 (Prdx6), during C. sinensis infection. Prdx6 overexpression suppressed intracellular free-radical generation by inhibiting NADPH oxidase2 and inducible nitric oxide synthase activation in the ESP-treated cholangiocarcinoma cells, substantially attenuating NF-κB-mediated inflammation. NF-κB overexpression decreased Prdx6 transcription levels by binding to two κB sites within the promoter. This transcriptional repression was compensated for by other ESP-induced redox-active transcription factors, including erythroid 2-related factor 2 (Nrf2), hypoxia inducible factor 1α (HIF1α), and CCAAT/enhancer-binding protein β (C/EBPβ). Distribution of immunoreactive Prdx6 and NF-κB was distinct in the early stages of infection in mouse livers but shared concomitant localization in the later stages. The intensity and extent of their immunoreactive staining in infected mouse livers are proportional to lesion severity and infection duration. The constitutive elevations of Prdx6 and NF-κB during C. sinensis infection may be associated with more severe persistent hepatobiliary abnormalities mediated by clonorchiasis.

Wound healing and cancer progression in Opisthorchis viverrini associated cholangiocarcinoma

Infection with the human liver fluke Opisthorchis viverrini induces cancer of the bile ducts, cholangiocarcinoma (CCA). It was shown previously that O. viverrini-secreted proteins accelerate wound resolution in human cholangiocytes. Recombinant Ov-GRN-1 (O. viverrini-derived gene encoding granulin-like growth factor) induced angiogenesis and accelerated mouse wound healing. Given the striking similarities of wound healing and cancer progression, here we discuss the major implications of this finding for an infection-induced cancer of major public health significance in the developing world.

Intrahepatic Duct Stones Harboring Ascariasis Ova: A Case Report

Ascariasis lumbricoides is one of the most common helminthic infestations in humans. Despite the fact that the prevalence of ascariasis in developed countries has been decreasing, biliary ascariasis can cause serious complications, such as acute cholangitis, pancreatitis, and liver abscess. Here we presented a rare ascariasis-related complication-hepatolithiasis.A 60-year-old female patient had symptoms of recurrent cholangitis. Abdominal computed tomography scan revealed left intrahepatic duct stones with left liver lobe atrophy. Endoscopic retrograde cholangiopancreatography was performed, but the stones could not be removed due to left main intrahepatic duct stenosis. The patient was treated with left hemi-hepatectomy. Unexpectedly, Ascaris ova were found on the histopathological examination. She received antihelminthic therapy orally and was on regular follow-up without any complications.Our study indicates that clinicians should be aware of biliary ascariasis in patients with hepatolithiasis, though not living in endemic areas.

Clonorchiasis

On Aug 21, 1875, James McConnell published in The Lancet his findings from a post-mortem examination of a 20-year-old Chinese man--undertaken at the Medical College Hospital in Calcutta, India--in whom he found Clonorchis sinensis in the bile ducts. Now, exactly 140 years later, we have a sound understanding of the lifecycle of this liver fluke, including key clinical, diagnostic, and epidemiological features. Developments in the so-called -omics sciences have not only advanced our knowledge of the biology and pathology of the parasite, but also led to the discovery of new diagnostic, drug, and vaccine targets. C sinensis infection is primarily related to liver and biliary disorders, especially cholangiocarcinoma. Clonorchiasis mainly occurs in east Asia, as a result of the region's social-ecological systems and deeply rooted cultural habit of consuming raw freshwater fish. The Kato-Katz technique, applied on fresh stool samples, is the most widely used diagnostic approach. Praziquantel is the treatment of choice and has been considered for preventive chemotherapy. Tribendimidine showed good safety and therapeutic profiles in phase 2 trials and warrants further investigation. Still today, the precise distribution, the exact number of infected people, subtle morbidities and pathogenesis, and the global burden of clonorchiasis are unknown. Integrated control strategies, consisting of preventive chemotherapy; information, education, and communication; environmental management; and capacity building through intersectoral collaboration should be advocated.

Development of a Health Education Modification Program Regarding Liver Flukes and Cholangiocarcinoma in High Risk Areas of Nakhon Ratchasima Province Using Self-Efficacy and Motivation Theory

A quasi-experimental study was conducted to develop a health education modification program based on self-efficacy and motivation regarding liver flukes and cholangiocarcinoma development in Keang Sanam Nang district, Nakhon Ratchasima province, Thailand. A total of 36 individuals were invited to participate in the program and were screened for population at risk of liver fluke infection and cholangiocarcinoma using SUT-OV-001 and SUT-CCA-001. Development of health education modification program regarding liver fluke and cholangiocarcinoma prevention included 3 steps: (1) preparation, (2) health education program, and (3) follow-up and evaluation. The study was implemented for 10 weeks. Pre-and-post-test knowledge was measured with questionnaires, Kuder-Richardson-20: KR-20 = 0.718,and Cronbach's Alpha Coefficient = 0.724 and 0.716 for perception and outcome expectation questionnaires. Paired and independent t-tests were applied for data analysis. The majority of the participants were female (55.6%), aged between ≤50 and 60 years old (36.1%), married (86.1%), education level of primary school (63.9%), agricultural occupation (80.6%), and income <4,000 Baht (44.4%). The results revealed that after the health education program, the experimental group had a mean score of knowledge, perception, and outcome expectation regarding liver fluke and cholangiocarcinoma prevention significantly higher than before participation and in the control group. In conclusion, this successful health education modification program for liver fluke and cholangiocarcinoma, therefore may useful for further work behavior modification in other epidemic areas.

Raw Fish Consuming Behavior Related to Liver Fluke Infection among Populations at Risk of Cholangiocarcinoma in Nakhon Ratchasima Province, Thailand

Opisthorchiasis is a health problem in rural communities of Thailand, particularly in the northeast and north regions. Therefore, this study aimed to investigate raw fish consuming behavior related to liver fluke infection among the population at risk for opisthorchiasis and cholangiocarcinoma (CCA). A cross-sectional descriptive study was conducted in Meuang Yang district, Nakhon Ratchasima province, northeast Thailand, between June and October 2015. Participants were screened for CCA, and samples who had a high score of CCA risk were purposively selected. A predesigned questionnaire was utilized to collect the data from all participants. X2-test was used for analysis of associations between demographic data and raw fish consumption. The results revealed that participants had past histories of stool examination (33.0%), liver fluke infection (21.0%), praziquantel use (24.0%), raw fish consumption (78.0%), relatives family consuming raw fish (73.0%), and relatives family with CCA (3.0%). Participants consumed several dished related to liver fluke infection, mainly raw fermented fish (13.0%), under smoked catfish (5.00%), raw pickled fish (4.00%), and raw spicy minced fish salad (3.00%). The most common types of cyprinoid fish were Barbodes gonionotus (39%), Hampala dispar (38%), Puntius brevis (37%), Cyclocheilichthys armatus (33%), Puntioplites proctozysron (32%), and Luciosoma bleekeri (30%), respectively. Participants had a low level of knowledge (mean=3.79, SD=0.74), moderate attitude (mean=7.31, SD=7.31) and practice (mean=38.64, SD=6.95) regarding liver fluke prevention and control. Demographic variables like age (>36 years old; X2-test=17.794, p-value=0.001), education (primary school; X2-test=18.952, p-value=0.001), marital status (married; X2-test=12.399, p-value=0.002), and income (<5,000 baht; X2-test=27.757, p-value=0.015) were significantly associated with raw fish consumption. This result indicates that the population had risk consumption for liver fluke infection particularly of various cyprinoid fishes that are 2nd intermediate hosts. Therefore, health education is required to improve their behavior.

Behavioral Modification Regarding Liver Fluke and Cholangiocarcinoma with a Health Belief Model Using Integrated Learning

This study aimed to modify behavior regarding liver fluke and cholangiocarcinoma prevention in Chumphuang district, Nakhon Ratchasima province, Thailand through integrated learning. A total of 180 participants were included through purposive selection of high-risk scores on verbal screening. Participants attended the health education program which applied the health belief model included family based, knowledge station based, academic merit based and community based learning. Data were collected using a questionnaire composed of 4 parts: 1) personal information, 2) knowledge, 3) perceived susceptibility, severity, benefits, and barriers, 4) practice regarding liver fluke and cholangiocarcinoma prevention. The result revealed that the majority were female (79.9%), age ≥60 years old (33.2%), primary school educational level (76.1%), and agricultural occupation (70.1%). The mean scores of knowledge, perception, and practice to liver fluke and cholangiocarcinoma prevention, before participated the integrative learning were low, moderate, and low, respectively. Meanwhile, the mean score of knowledge, perceived susceptibility, severity, benefits, and barriers, and practice regarding liver fluke and cholangiocarcinoma prevention, were higher with statistical significance after participation in the integrated learning. This finding indicates that health education programs may successfully modify health behavior in the rural communities. Therefore they may useful for further work behavior modification in other epidemic areas.

Sonographic features of intestinal and biliary ascariasis in childhood: case report and review of the literature

Despite the fact that Ascaris lumbricoides is one of the commonest intestinal infections in developing countries, there are very few reports in the literature about the sonographic findings of intestinal and biliary ascariasis in childhood. The clinical manifestations, diagnostic procedures and imaging appearance of intestinal and biliary ascariasis in two patients are discussed with a brief review of the literature.

Annexin A1: A new immunohistological marker of cholangiocarcinoma

AIM: To evaluate a new immunohistological marker, annexin A1 (ANXA1), in cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC).

METHODS: Expression of ANXA1 protein was investigated in liver tissues from patients with CCA and HCC by immunohistochemistry. Its expression on differences stages of tumor development was investigated in hamster CCA tissues induced by Opisthorchis viverrini and N-nitrosodimethylamine. Moreover, mRNA expression of ANXA1 was assessed in CCA cell lines by quantitative real-time polymerase chain reaction and silencing of ANXA1 gene expression using small interfering RNA.

RESULTS: In human CCA tissue arrays, immunohistochemical analysis revealed that the positive expression of ANXA1 was 94.1% (64/68 cases) consisting of a high expression (66.2%, 45/68 cases) and a low expression (33.8%, 23/68 cases). However, expression of ANXA1 protein was negative in all histologic patterns for HCC (46/46 cases) and healthy individuals (6/6 cases). In hamster with opisthorchiasis-associated CCA, the expression of ANXA1 was observed in the cytoplasm of inflammatory cells, bile duct epithelia and tumor cells. Grading scores of ANXA1 expression were significantly increased with tumor progression. In addition, mRNA expression of ANXA1 significantly increased in all of the various CCA cell lines tested compared to an immortalized human cholangiocyte cell line (MMNK1). Suppressing the ANXA1 gene significantly reduced the matrix metalloproteinase (MMP) 2 and MMP9, and transforming growth factor-β genes, but increased nuclear factor-κB gene expression.

CONCLUSION: ANXA1 is highly expressed in CCA, but low in HCC, suggesting it may serve as a new immunohistochemical marker of CCA. ANXA1 may play a role in opisthorchiasis-associated cholangiocarcinogenesis.

[Correlation between liver sonographic findings and clinical manifestations of clonorchiasis]

OBJECTIVE

To study the correlation between sonographic findings of the intrahepatic bile duct and liver and clinical symptoms and signs of clonorchiasis.

METHODS

The data of sonographic findings of intrahepatic bile duct and liver and clinical symptoms and signs of 98 patients with clonorchiasis were collected and analyzed.

RESULTS

There were 40 cases in light degree of the II , III intrahepatic bile duct dilatation, 27 cases in middle degree, and 31 cases in heavy degree. There were 4 cases of intrahepatic bile duct dilatation and liver patchy or nodular lesions of slightly stronger echo. The mild expansion of intrahepatic bile duct was found in the patients with no obvious clinical signs and symptoms. The middle and heavy degrees of expansion were found in the patients with obvious clinical signs and symptoms. There were significantly difference between them (chi2 = 43.57, P < 0.05). The incidence of middle and heavy degrees of expansion in patients with cholecystitis, pancreatitis, liver cirrhosis and hepatocellular carcinoma and cholangiocarcinoma was much higher than that in patients with intrahepatic bile duct stones (chi2 = 4.873, P < 0.05).

CONCLUSION

Bile duct dilatation is closely correlated with the clinical symptoms and signs. This connection helps the diagnosis of clonorchiasis.

The current status of opisthorchiasis and clonorchiasis in the Mekong Basin

This review highlights the current status and control of liver fluke infections in the Mekong Basin countries where Opisthorchis and Clonorchis are highly endemic. Updated data on prevalence and distribution have been summarized from presentations in the "96 Years of Opisthorchiasis. International Congress of Liver Flukes". It is disturbing that despite treatment and control programs have been in place for decades, all countries of the Lower Mekong Basin are still highly endemic with O. viverrini and/or C. sinensis as well as alarmingly high levels of CCA incidence. A common pattern that is emerging in each country is the difference in transmission of O. viverrini between lowlands which have high prevalence versus highlands which have low prevalence. This seems to be associated with wetlands, flooding patterns and human movement and settlement. A more concerted effort from all community, educational, public health and government sectors is necessary to successfully combat this fatal liver disease of the poor.

Tracing of the Bile-chemotactic migration of juvenile Clonorchis sinensis in rabbits by PET-CT

Background

Adult Clonorchis sinensis live in the bile duct and cause clonorchiasis. It is known that the C. sinensis metacercariae excyst in the duodenum and migrate up to the bile duct through the common bile duct. However, no direct evidence is available on the in vivo migration of newly excysted C. sinensis juveniles (CsNEJs). Advanced imaging technologies now allow the in vivo migration and localization to be visualized. In the present study, we sought to determine how sensitively CsNEJs respond to bile and how fast they migrate to the intrahepatic bile duct using PET-CT.

Methodology/Principal Findings

CsNEJs were radiolabeled with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG). Rabbits with a gallbladder contraction response to cholecystokinin-8 (CCK-8) injection were pre-screened using cholescintigraphy. In these rabbits, gallbladders contracted by 50% in volume at an average of 11.5 min post-injection. The four rabbits examined were kept anesthetized and a catheter inserted into the mid duodenum. Gallbladder contraction was stimulated by injecting CCK-8 (20 ng/kg every minute) over the experiment. Anatomical images were acquired by CT initially and dynamic PET was then carried out for 90 min with a 3-min acquisition per frame. Twelve minutes after CCK-8 injection, about 3,000 ¹⁸F-FDG-labeled CsNEJs were inoculated into the mid duodenum through the catheter. Photon signals were detected in the liver 7–9 min after CsNEJs inoculation, and these then increased in the whole liver with stronger intensity in the central area, presenting that the CsNEJs were arriving at the intrahepatic bile ducts.

Conclusion

In the duodenum, CsNEJs immediately sense bile and migrate quickly with bile-chemotaxis to reach the intrahepatic bile ducts by way of the ampulla of Vater.

Clonorchis sinensis adults habituating in the bile duct cause clonorchiasis endemic in East Asian countries, in which about 15–20 million people are supposedly infected. It has previously been reported that C. sinensis metacercariae excyst in the duodenum and that the juvenile flukes migrate to the bile duct through the ampulla of Vater in 4–7 hours. Recently advanced imaging technologies have enabled visualization of movements and localizations of parasites in mammalian hosts. From present study, we found the following: newly excysted C. sinensis juveniles (CsNEJs) were efficiently in vitro radiolabeled with ¹⁸F-FDG since CsNEJs have glucose transporters; CCK-8-induced gallbladder contraction was various rabbit to rabbit; CsNEJs promptly recognized bile and migrated up the duodenum to reach the intrahepatic bile ducts by way of the ampulla of Vater and the common bile duct as early as 7–9 minutes after inoculation. Some CsNEJs responding slowly to the bile delayed arriving at the distal bile capillaries. It was visualized for the first time that the CsNEJs migrate quickly within 10–20 minutes from the duodenum to the intrahepatic bile duct. These findings provide fundamental information on the migration of parasites living in the biliary passages of mammals.

Opisthorchiasis and Opisthorchis-associated cholangiocarcinoma in Thailand and Laos

Liver fluke infection caused by Opisthorchis viverrini is a major public health problem in Thailand and the Lao People's Democratic Republic (Lao PDR; Laos). Currently, more than 600 million people are at risk of infection with these fish-borne trematodes and/or their close relatives. Opisthorchiasis has been studied extensively in Thailand, where about 8 million people are infected with the liver fluke. Here we review the pathogenesis, control and re-emergence of O. viverrini infection, in particular in Thailand and, to a lesser extent in Lao PDR given the contiguous geographical range of O. viverrini through these two regions. We also review the association of O. viverrini infection and cholangiocarcinoma, bile duct cancer, and highlight new findings on pathogenesis of liver fluke-induced cholangiocarcinogenesis. Last, we comment on national control strategies in Thailand for the control of O. viverrini infection aimed at reduction in the prevalence of O. viverrini-associated liver cancer in the longer term.

Expression of oxysterol binding protein isoforms in opisthorchiasis-associated cholangiocarcinoma: a potential molecular marker for tumor metastasis

Oxysterols are oxygenated derivatives of cholesterol generated by enzymatic reactions mediated by cytochrome P450 family enzymes or by inflammation-associated non-enzymatic reactions. Oxysterol binding proteins (OSBPs) are cytosolic high affinity receptors for oxysterols. We previously found that OSBPL-8 is upregulated in liver fluke (Opisthorchis viverrini)-induced hamster cholangiocarcinoma (CCA). Our aims were to determine the expression patterns of OSBP isoforms in human CCA tissues and to evaluate whether OSBPs could be used as molecular markers for the identification of blood-borne CCA metastasis. Expression levels of OSBP1, OSBP2, OSBPL-7 and OSBPL-8 in CCA tissues were detected using qRT-PCR and immunohistochemistry. Expression of OSBPs at mRNA level in the blood of CCA patients was also investigated. We confirmed increased expression of OSBPL-8 in O. viverrini -induced hamster CCA tissues. Moreover, increased expression of OSBP1, OSBP2, OSBPL-7 and OSBPL-8 was seen in human CCA tissues. Notably, a significant increased level of OSBPL-7 mRNA was observed in tumor compared to non-tumor liver tissue. Immunohistochemistry supported the mRNA results, in that OSBPL-7 protein was over-expressed in cancer cells and hepatocytes but not in normal biliary cells and surrounding inflammatory cells. Interestingly, in our preliminary results, significantly higher levels of OSBP2 and OSBPL-7 mRNA were seen in blood samples from CCA patients than in healthy controls. These results suggest that OSBP2 and OSBPL-7 might serve as molecular markers for the identification of CCA metastasis in the bloodstream.

Opisthorchis viverrini-antigen induces expression of MARCKS during inflammation-associated cholangiocarcinogenesis

Myristoylated alanine rich C kinase substrate (MARCKS) has been implicated in PKC-mediated membrane-cytoskeleton alterations that underlie lipopolysaccharide (LPS)-induced macrophage responses. MARCKS is postulated to be involved in inflammation-associated CCA based on its overexpression in cholangiocarcinoma (CCA) and inflammatory cells. The aims of this study were to investigate localization patterns of MARCKS in hamster and human tissue during cholangiocarcinogenesis and to examine the involvement of MARCKS in inflammation. MARCKS protein expression was found prominently in inflammatory cells of Opisthorchis viverrini-treated as well as O. viverrini plus N-nitrosodimethylamine (NDMA)-treated hamsters from week 2 to week 3 of treatment. The positive signal decreased during week 4 to week 12, then increased again at week 26 when CCA developed. At the last time point the expression of MARCKS was observed in both cancer and inflammatory cells. MARCKS protein expression was also found in inflammatory cells, including macrophages in human CCA tissues. O. viverrini excretory/secretory products or worm antigen induced MARCKS mRNA and protein expression in a dose- and time-dependent manner in the human U937 macrophage cell line. The relative mRNA expression of MARCKS in white blood cells of O. viverrini-infected patients was significantly higher than in healthy subjects (P = 0.02). Thus, MARCKS is significantly expressed in macrophages and plays a role in inflammation-related CCA induced by O. viverrini.

Molecular expression and enzymatic characterization of thioredoxin from the carcinogenic human liver fluke Opisthorchis viverrini

The human liver fluke, Opisthorchis viverrini, induces inflammation of the hepatobiliary system. Despite being constantly exposed to inimical oxygen radicals released from inflammatory cells, the parasite survives for years. Defense against oxidative damage can be mediated through glutathione and/or thioredoxin utilizing systems. Here, we report the molecular expression and biochemical characterization of a thioredoxin (Trx) from O. viverrini. O. viverrini Trx cDNA encoded a polypeptide of 105 amino acid residues, of molecular mass 11.63 kDa. The predicted protein has similarity to previously characterized thioredoxins with 26-51% identity. Recombinant O. viverrini Trx (Ov-Trx-1) was expressed as soluble protein in E. coli. The recombinant protein showed insulin reduction activity and supported the enzymatic function of O. viverrini thioredoxin peroxidase. Expression of Ov-Trx-1 at mRNA and protein levels was observed in all obtainable developmental stages of the liver fluke. Ov-Trx-1 was also detected in excretory-secretory products released by adult O. viverrini. Immunohistochemistry, Ov-Trx-1 was expressed in nearly all parasite tissue excepted ovary and mature sperms. Interestingly, Ov-Trx-1 was observed in the infected biliary epithelium but not in normal bile ducts. These results suggest that Ov-Trx-1 is essential for the parasite throughout the life cycle. In the host-parasite interaction aspect, Ov-Trx-1 may support thioredoxin peroxidase in protecting the parasite against damage induced by reactive oxygen species from inflammation.

RNA interference targeting cathepsin B of the carcinogenic liver fluke, Opisthorchis viverrini

Functional genomics have not been reported for Opisthorchis viverrini or the related fish-borne fluke, Clonorchis sinensis. Here we describe the introduction by square wave electroporation of Cy3-labeled small RNA into adult O. viverrini worms. Adult flukes were subjected to square wave electroporation employing a single pulse for 20 ms of 125V in the presence of 50 μg/ml of Cy3-siRNA. The parasites tolerated this manipulation and, at 24 and 48 h after electroporation, fluorescence from the Cy3-siRNA was evident throughout the parenchyma of the worms, with strong fluorescence evident in the guts and reproductive organs of the adult worms. Second, other worms were treated using the same electroporation settings with double stranded RNA targeting an endogenous papain-like cysteine protease, cathepsin B. This manipulation resulted in a significant reduction in specific mRNA levels encoding cathepsin B, and a significant reduction in cathepsin B activity against the diagnostic peptide, Z-Arg-Arg-AMC. This appears to be the first report of introduction of reporter genes into O. viverrini and the first report of experimental RNA interference (RNAi) in this fluke. The findings indicated the presence of an intact RNAi pathway in these parasites which, in turn, provides an opportunity to probe gene functions in this neglected tropical disease pathogen.

A record of Pseudamphistomum truncatum (Rudolphi, 1819) (Digenea, Opisthorchiidae) in the Eurasian otter (Lutra lutra L.) from Poland

Opisthorchid digenean Pseudamphistomum truncatum (Rudolphi, 1819) was isolated from liver bile ducts of the Eurasian otter (Lutra lutra) found dead in the fishing pond complex near Wrocław (Lower Silesia, SW. Poland) in March 2009. Since this is the first record of the parasite in the otter from Poland, the description, biometrical data and figure are presented.

Descriptive epidemiology of cholangiocarcinoma and clonorchiasis in Korea

In 2009, infection with the liver fluke Clonorchis sinensis (C. sinensis) was classified as "carcinogenic to humans" (Group 1) based on its involvement in the etiology of cholangiocarcinoma by the International Agency for Research on Cancer. However, little is known about the descriptive epidemiology of cholangiocarcinoma in Korea. We examined incidence trends of intrahepatic and extrahepatic cholangiocarcinomas, using data from the Korea National Cancer Incidence database for 1999-2005. The prevalence of C. sinensis infection was estimated from a recent population-based survey in rural endemic areas. Cholangiocarcinoma incidence rates are currently rising, even while primary liver cancer incidence rates are decreasing. Annual percent changes in cholangiocarcinoma incidence rates were 8% for males and 11% in females. Known areas of C. sinensis endemicity showed high incidence rates of cholangiocarcinoma. The positivity of C. sinensis eggs in stool samples from endemic areas was more than 25% of adults tested during 2005-2008. From a meta-analysis, the summary odds ratio for cholangiocarcinoma due to C. sinensis infection was 4.7 (95% confidence interval: 2.2-9.8). Approximately 10% of cholangiocarcinomas in Korea were caused by chronic C. sinensis infections. More specific policies, including health education and an extensive effort for early detection in endemic areas, are needed.

A granulin-like growth factor secreted by the carcinogenic liver fluke, Opisthorchis viverrini, promotes proliferation of host cells

The human liver fluke, Opisthorchis viverrini, infects millions of people throughout south-east Asia and is a major cause of cholangiocarcinoma, or cancer of the bile ducts. The mechanisms by which chronic infection with O. viverrini results in cholangiocarcinogenesis are multi-factorial, but one such mechanism is the secretion of parasite proteins with mitogenic properties into the bile ducts, driving cell proliferation and creating a tumorigenic environment. Using a proteomic approach, we identified a homologue of human granulin, a potent growth factor involved in cell proliferation and wound healing, in the excretory/secretory (ES) products of the parasite. O. viverrini granulin, termed Ov-GRN-1, was expressed in most parasite tissues, particularly the gut and tegument. Furthermore, Ov-GRN-1 was detected in situ on the surface of biliary epithelial cells of hamsters experimentally infected with O. viverrini. Recombinant Ov-GRN-1 was expressed in E. coli and refolded from inclusion bodies. Refolded protein stimulated proliferation of murine fibroblasts at nanomolar concentrations, and proliferation was inhibited by the MAPK kinase inhibitor, U0126. Antibodies raised to recombinant Ov-GRN-1 inhibited the ability of O. viverrini ES products to induce proliferation of murine fibroblasts and a human cholangiocarcinoma cell line in vitro, indicating that Ov-GRN-1 is the major growth factor present in O. viverrini ES products. This is the first report of a secreted growth factor from a parasitic worm that induces proliferation of host cells, and supports a role for this fluke protein in establishment of a tumorigenic environment that may ultimately manifest as cholangiocarcinoma.

[Intrabiliary rupture of hepatic hydatid cysts: results of 17 years' experience]

Between 1990 and 2006 in the III-rd Surgical Clinic Cluj-Napoca, 366 pacients with hepatic hydatid cyst were admitted and underwent surgery; 81 (22.13%) of them, who had a cyst-biliary comunication, were retrospectively reviewed: 52 (64.2%) had an occult communications and 29 (35.8%) had a frank intrabiliary rupture. The sex ratio was M/F=46/35 with a mean age of 44.5 years and with ages between 17 and 73 years. Choledochotomy, evacuation of parasitic material and lavage of the CBP were performed in all patients with frank intrabiliary rupture. In 25 patients, partial pericystectomy and choledochoduodenostomy/T-tube drainage of CBP was performed. Internal drainage by a Roux-en-Y pericystectojejunostomy and biliodigestive anastomosis was carried out in 2 patients, while other two patients underwent external drainage of cystic cavity and T-tube drainage of CBP. 15 patients (51.7%) had postoperative external bile leaks (fistulas). Occult communications were managed by partial pericystectomy +/- narrowing of the residual cavity (capitonage with an omentum flap or invagination of the fibrosis capsule margins into the cavity) in 35 patients (67.3%) while in 10 patients (19.2%) internal drainage by a Roux-en-Y pericystectojejunostomy was carried out. Regional resection of the liver was performed in 4 cases (7.7%) and external drainage of residual cavity in 3 patients (5.7%). 13 patients (25%) had postoperative external bile leaks (fistulas). The mean postoperative hospitalisation was 20 days with the range 5-85 days. The mortality rate was 2.4% (2 patients): one died due to septicemia and MOFS and the other due to pulmonary thromboembolism.

CONCLUSION

Postoperative bile leaks (fistulas) fallowing conservative surgery of ruptured hydatid hepatic cyst into the biliary tract are not rare regardless of the type of rupture (frank or occult). Although the opening of the biliary duct is sutured, the risk of biliary fistulas is not clearly corelated with this approach; in such cases internal drainage provides a good alternative with low morbidity.

Cholangiocarcinoma in experimental hamsters with long-standing Opisthorchis viverrini infection

Liver fluke infection of Opisthorchis viverrini (O. viverrini) is closely associated with several hepatobiliary diseases including cholangiocarcinoma (CCA), but no reports have described these diseases in chronic and long-standing experimental opisthorchiasis in hamsters more than 10 months of age. A longer period of infection could induce different pathological lesions. To prove the hypothesis, we therefore sequentially investigated histological changes of the hepatobiliary system in 4 groups of hamsters: O. viverrini infection (OV group) for up to 20 months; O. viverrini infection combined with short-term DMN (OV+DMN group) until 7 months; long-term treatment with DMN (DMN group) to 7 months; and normal controls for up to 20 months. Pathological changes in hamsters of the OV group gradually increased. Induction of CCA in this study was apparent with all three protocols. Importantly, this is the first report of CCA-induction in hamsters solely with long-term opisthorchiasis for up to 20 months. Although the histopathology of CCA in the OV group showed some differences in appearance from the OV+DMN and DMN groups, overall, O. viverrini itself can really induce CCA. In addition, this study confirms the previous studies both in vitro and in vivo on of effects of parasites and their metabolic products inducing cell proliferation, resulting in cholangiocarcinogenesis.

Mutations of KRAS and TP53 in a minor proportion of Opisthorchis viverrini-associated cholangiocarcinomas in a hamster model

BACKGROUND/AIMS

KRAS oncogene and TP53 tumor suppressor gene have been known as common genes involving in many cancers including cholangiocarcinoma (CCC). Activation of these genes could lead to uncontrolled proliferation and cancer ultimately. The aim of this study was to investigate mutation of KRAS exon 1 and TP53 exon 5-8 in Opisthorchis viverrini (OV)-induced cholangiocarcinoma (CCA) in a hamster model.

METHODS

Twenty-seven CCAs were obtained from Syrian golden hamsters induced by OV infection and N-nitrosodimethylnitrosamine (N-NDDM) administration. The tumor tissues were processed for histopathology. Genomic DNA extracted from paraffin sections by microdissection was amplified for KRAS exon 1 and TP53 exon 5-8 mutations by PCR-direct sequencing.

RESULTS

Histopathologically, the tumors were classified into tubular (81.5%, 22/27), papillary (3.7%, 1/27), mucinous (3.7%, 1/27) and mixed types (11.1%, 3/27). Of the 27 CCAs, PCR-direct sequencing of KRAS showed G[see text]A transition at codon 37 exon 1 in one CCA sample (3.70%). Point mutations of p53 exon 6 (G[see text]C transversion at codon 119 and 218 and A[see text]C transversion at codon 217) were found in 3 CCA samples (11.1%).

CONCLUSIONS

The results suggest that mutation of TP53 particularly at exon 6 may be involved in cholangiocarcinogenesis and a novel mutation of KRAS exon 1 was firstly reported in OV-induced hamster CCA.

Granulomatous, hepatolithiasis and hepatomegaly caused by Capillaria hepatica infection: first case report of Thailand

This is the first case report in Thailand of a Capillaria hepatica infection causing a granulomatous hepatic lesion, bile duct dilatation, hepatolithiasis and hepatomegaly. The patient's chief complaint was abdominal pain with fever and chills. Imaging of the liver revealed a 3-cm mass in the postero-inferior sub-segment of the right lobe of the liver with bile duct dilatation. Right hepatectomy and cholecystectomy were performed. Gross pathology of the right hepatectomy revealed focal intrahepatic duct dilatation with prominent periductal fibrosis. The histopathological section revealed chronic inflammation and some granuloma formation surrounding the bile ducts, generalized portal infiltration, prominence of eosinophils and hepatolithiasis. Histopathotogical section revealed oblique sections of C. hepatica egg (size 35.4+/-6.38 microm in width) and brown amorphous pigment.

Phylogeny of Coccomyxa (Myxosporea: Myxidiidae) spp. with the description of a new species from Bathygobius cyclopterus (Gobiidae) in the northern Red Sea

Two species of Coccomyxa Léger et Hesse, 1907, one of the least studied myxosporean genera, are reported from shallow coastal waters in the Gulf of Eilat, Red Sea, Israel. A new species, Coccomyxajirilomi sp. n. is described from the spotted frillgoby Bathygobius cyclopterus (Valenciennes) (Gobiidae). It forms polysporous plasmodia that invade the liver and form packed clusters inside the bile ductules. Plasmodia also occur in the bile ducts and gall bladder of the host, attached to the epithelial lining or free floating in the bile. Infected hepatic bile ductules packed with plasmodia were partially occluded, with evidence of cholestasis, periductular fibrosis and pericholangitis. The mature spore is ellipsoid, has smooth valves and contains a single polar capsule with the polar filament arranged in 4-5 oblique coils. Spore dimensions are 9.0-11.3 x 5.0-7.0 microm. A second species, Coccomyxa sp., with smaller 7.6-9.6 x 4.2-5.2 microm and more delicate spores, was found in the gall bladder of the rippled rockskipper, Istiblennius edentulus (Forster et Schneider) (Blenniidae). The small subunit (SSU) rDNA sequence analysis of both Coccomyxa species suggests that they are closely related to members of the genera Myxidium, Zschokkella and Auerbachia, whose members infect the gall bladder of marine fish.

A NEW DICROCOELIID FROM THE BANK VOLE CLETHRIONOMYS GLAREOLUS (RODENTIA: MICROTIDAE) FROM POLAND

A new dicrocoeliid trematode, Brachylecithum glareoli n. sp., is described from the biliary ducts of the bank vole, Clethrionomys glareolus, in southwest Poland. This is the first dicrocoeliid species described in rodents from Poland. It is characterized mainly by the maximum body width at the level of the vitellaria; large, longitudinally oval testes; round, or transversely oval, ovary that is smaller than the testes; vitellaria located in the midbody; cirrus sac dorsally overlapping ventral sucker, but never reaching beyond half of its length; and large, distinctly elongated eggs.

Multiple hepatic nodules: rare manifestation of clonorchiasis

A 38-year-old man was admitted due to intermittent right upper quadrant pain for 1 month. Leukocytosis with marked eosionphilia and elevated serum alkaline phosphatase were noted. Stool examinations revealed no parasites or ova. Ultrasonography and computed tomography disclosed multiple hepatic tumors. Biopsy of the hepatic tumor was performed due to non-conclusive imaging studies and revealed eosinophil infiltration in portal areas only. Endoscopic retrograde cholangiography showed mild dilatation with irregularity of bilateral intrahepatic ducts, compatible with chronic cholangitis. Bile was aspirated and biliary lavage with normal saline was performed during endoscopy-guided biliary cannulation. Microscopic examination of the aspirate showed the characteristic ova of Clonorchis sinensis. The patient received Praziquantel therapy for 1 day. Abdominal pain reduced in intensity gradually. Eosinophilia and multiple hepatic lesions resolved after adequate treatment of Clonorchis sinensis. The rare manifestation of multiple hepatic tumors in Clonorchis sinensis should be differentiated from other primary or metastatic neoplasms, while biliary lavage for parasite ova is a valuable diagnostic tool when stool examination is negative.

iNOS-dependent DNA damage via NF-kappaB expression in hamsters infected with Opisthorchis viverrini and its suppression by the antihelminthic drug praziquantel

Inflammation-mediated DNA damage triggered by Opisthorchis viverrini (OV) infection is a major risk factor of cholangiocarcinoma (CCA). We have recently reported that nitrative and oxidative DNA damage participates in CCA development caused by repeated infection with OV [Pinlaor et al., Carcinogenesis 2004; 25:1535-42]. Therefore, to clarify the preventive effect of the antihelminthic drug praziquantel against cholangiocarcinogenesis, we assessed the effect of this drug on nitrative and oxidative DNA damage, including the formation of 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), and the expression of inducible nitric oxide synthase (iNOS) by immunohistochemistry in OV-infected hamsters. We also examined the expression of nuclear factor-kappaB (NF-kappaB), which functions as a tumor promoter in inflammation-associated cancer. Our results showed that although 1-week treatment with praziquantel did not kill parasites completely in hamsters on days 14 and 30, this drug dramatically reduced inflammatory cell infiltration. Double immunofluorescence staining showed that drug treatment almost completely diminished OV-induced 8-nitroguanine and 8-oxodG formation in bile duct epithelial cells. Quantitative analysis using an electrochemical detector coupled to HPLC revealed that 8-oxodG level in the liver of OV-infected hamsters was significantly decreased by drug treatment (p<0.05). Western blotting and immunohistochemistry revealed that the expression of NF-kappaB and iNOS in bile duct epithelium was reduced by drug treatment. The amount of nitrate plus nitrite in the liver and plasma was significantly decreased after drug treatment. It is concluded that praziquantel can exhibit a preventive effect against OV-induced cholangiocarcinoma by inhibiting iNOS-dependent DNA damage through not only elimination of parasites but also a potential antiinflammatory effect.

Prognostic significance of microsatellite alterations at 1p36 in cholangiocarcinoma

AIM: To investigate loss of heterozygosity (LOH) and microsatellite instability (MSI) on the chromosomal region 1p36-pter in cholangiocarcinoma (CCA) patients and determine the association between microsatellite alterations and clinicopathological parameters.

METHODS: Ten polymorphic microsatellite markers were determined for LOH and MSI using GS-3000 gel scan fragment autoanalyzer.

RESULTS: Sixty-eight out of 90 cases (75.6%) showed LOH in one or more loci. LOH was found most frequently at D1S199 (40.0%), D1S507 (34.6%), D1S2845 (30.5%), and D1S2734 (30.1%). MSI was found in 34 of 90 cases (37.8%) at one or more loci. Fine mapping at 1p36 showed two distinctive regions of common loss, which were D1S2845 and the 25.5-cM region between D1S507 and D1S2734, indicating the existence of putative tumor suppressor genes that is likely to play important roles in the development of CCA. Patients with LOH at D1S234 showed less lymphatic invasion (P = 0.017), whereas patients with LOH at D1S2676 exhibited more lymphatic invasion than those without (P = 0.031). LOH at D1S2845 showed a significant correlation with nerve invasion (P = 0.029). Moreover, patients who demonstrated MSI at D1S228 showed a poor prognosis (P = 0.0026).

CONCLUSION: Allelic loss plays a major role in microsatellite alterations at chromosome 1p36, which may contribute to carcinogenesis and pathogenesis of liver fluke related CCA and these alterations can be used as molecular prognostic indicators for CCA patients.

Amplification of D22S283 as a favorable prognostic indicator in liver fluke related cholangiocarcinoma

AIM: To analyze the DNA copy number of target genes NF2, TIMP3, ST13, TOB2, BIK, and TP and the reference microsatellite markers D22S283, D22S423, and D22S274 mapped on 22q12-qter in liver fluke related cholangiocarcinoma (CCA) and define its correlation with clinical parameters.

METHODS: Quantitative real time PCR (qPCR) was used for determining allelic imbalances in 65 liver fluke related CCA tissues. Statistical correlations between allelic imbalances and clinicopathological parameters, i.e. age, sex, tumor stage, histological type, blood vessel invasion, nerve invasion and lymphatic invasion were evaluated by means of the χ² test. Cox regression analysis was used for determining patient’s survival.

RESULTS: Amplifications of the TP (22q13.33), TOB2 (22q13.2-13.31), D22S283 (22q12.3), TIMP3 (22q12.3) and NF2 (22q12.2) were found in 35 (53.8%), 28 (43.1%), 27 (41.5%), 24 (36.9%), and 24 (36.9%), respectively. Losses at the D22S423 (22q13.1-13.2) and BIK (22q13.31) were detected in 26 (40%) and 23 (35.4%), respectively. Significant correlations were observed between lymphatic invasion and allelic losses of BIK (P = 0.025) and D22S283 (P = 0.041). Univariate and multivariate Cox regression analysis revealed D22S283 amplification as an independent predictor of good prognosis (P = 0.006, death hazard ratio = 0.411, 95% CI = 0.217-0.779) and blood vessel invasion as an independent poor prognostic factor (P = 0.042, death hazard ratio = 1.911, 95% CI = 1.022-3.571) in CCA patients.

CONCLUSION: This study provides evidence for the involvement of gene amplification and deletion on chromosome 22q in liver fluke related CCA. This is the first report of D22S283 amplification as an independent indicator of favorable prognosis in liver fluke related CCA.

Cryptosporidium parvum infects human cholangiocytes via sphingolipid-enriched membrane microdomains

Cryptosporidium parvum attaches to intestinal and biliary epithelial cells via specific molecules on host-cell surface membranes including Gal/GalNAc-associated glycoproteins. Subsequent cellular entry of this parasite depends on host-cell membrane alterations to form a parasitophorous vacuole via activation of phosphatidylinositol 3-kinase (PI-3K)/Cdc42-associated actin remodelling. How C. parvum hijacks these host-cell processes to facilitate its infection of target epithelia is unclear. Using specific probes to known components of sphingolipid-enriched membrane microdomains (SEMs), we detected aggregation of host-cell SEM components at infection sites during C. parvum infection of cultured human biliary epithelial cells (i.e. cholangiocytes). Activation and membrane translocation of acid-sphingomyelinase (ASM), an enzyme involved in SEM membrane aggregation, were also observed in infected cells. Pharmacological disruption of SEMs and knockdown of ASM via a specific small interfering RNA (siRNA) significantly decreased C. parvum attachment (by approximately 84%) and cellular invasion (by approximately 88%). Importantly, knockdown of ASM and disruption of SEMs significantly blocked C. parvum-induced accumulation of Gal/GalNAc-associated glycoproteins at infection sites by approximately 90%. Disruption of SEMs and knockdown of ASM also significantly blocked C. parvum-induced activation of host-cell PI-3K and subsequent accumulation of Cdc42 and actin by up to 75%. Our results suggest an important role of SEMs for C. parvum attachment to and entry of host cells, likely via clustering of membrane-binding molecules and facilitating of C. parvum-induced actin remodelling at infection sites through activation of the PI-3K/Cdc42 signalling pathway.

Ultrasound screening for Opisthorchis viverrini-associated cholangiocarcinomas: experience in an endemic area

In Thailand, liver cancer is the most common malignancy in males and the third most common among females. In the Northeast region, cholangiocarcinoma (CHCA) is the prevalent type, with Opisthorchis viverrini (OV), an endemic liver fluke, being considered the cause. We evaluated the role of ultrasound (U/S) for cholangiocarcinoma screening as part of a larger cohort to characterize the linkage between liver fluke infestation and CHCA in Khon Kaen (Northeast Thailand). Most people (77%) had normal U/S findings while only 0.5% had suspected CHCA; thus, U/S should be used primarily for those with the highest risk, presenting symptoms and/or being OV positive.

Immunohistochemical expression of mismatch repair genes: A screening tool for predicting mutator phenotype in liver fluke infection-associated intrahepatic cholangiocarcinoma

AIM: To clarify possible contributions of DNA mismatch repair (MMR) system in carcinogenesis of liver fluke infection-associated intrahepatic cholangiocarcinoma (ICC) by using immunohistochemical assay.

METHODS: A total of 29 ICC samples, which had been assessed for genomic instability by a PCR-based method, were used for study. They were examined immunohistochemically to demonstrate protein expression of two MMR genes, hMSH2 and hMLH1. Results obtained were compared with their mutator phenotype assessed previously.

RESULTS: Either hMSH2 or hMLH1 protein was obviously expressed in 28 of 29 (96.6%) ICC samples. Positive nuclear localization of hMSH2 or hMLH1 protein was observed in 86.2% (25/29) or 93.1% (27/29) ICC cases, respectively, while their negative nuclear reactivity was only detected in 13.8% (4/29) or 6.9% (2/29) ICC cases analyzed, respectively.

CONCLUSION: Our study, probably for the first time, showed through immunohistochemical detection of hMSH2 and hMLH1 gene that DNA MMR system does not play a prominent role in liver fluke infection-associated cholangiocarcinogenesis. These results confirm previous findings on mutational status of these genes assessed through a PCR-based method. The immunohistochemical analysis has proven to be an effective and sensitive approach for screening MMR deficiency regardless of somatic inactivation or promoter hypermethylation of hMSH2 and/or hMLH1 gene. Furthermore, immunohistochemistry is more advantageous compared to mutator phenotyping assay in terms of simplicity, less time consuming and cost effectiveness for screening possible involvements of target MMR genes in tumorigenesis.

Clonorchiasis: an update

Clonorchis sinensis, the Chinese or oriental liver fluke, is an important human parasite and is widely distributed in southern Korea, China (including Taiwan), Japan, northern Vietnam and the far eastern part of Russia. Clonorchiasis occurs in all parts of the world where there are Asian immigrants from endemic areas. The human and animal reservoir hosts (dogs, pigs, cats and rats) acquire the infection from the ingestion of raw fish containing infectious metacercariae. The first intermediate snail hosts are mainly species of Parafossarulus and Bithynia. Numerous species of freshwater fish serve as the second intermediate hosts of C. sinensis. Extensive studies of clonorchiasis during several decades in Japan, Korea, China and other countries have shown much progress in proving its morphological features including ultrastructure, biology, pathogenesis, epidemiology, clinical manifestations and chemotherapy. The present review deals with mainly current results obtained on the epidemiological, pathological and clinical aspects, as well as control measures in endemic areas. As for the complications of clonorchiasis, formation of calculi in the intrahepatic biliary passages is one of the most characteristic pathological features. It is sometimes accompanied by suppurative cholangitis, cholecystitis, cholangiohepatitis and ultimately can cause cholangiocarcinoma. Experimental results on the relationship to the occurrence of cholangiocarcinoma are presented. Clinical diagnosis by radiological findings including cholangiography, sonography and computerized tomography as well as magnetic resonance imaging for biliary or pancreatic ducts are outlined. Current studies on immunology and molecular biology of C. sinensis were introduced. Praziquantel is the drug of choice for clonorchiasis. The most effective regimen is 25 mg kg(-1) three times daily (total dose, 75 mg kg(-1)) administered orally at 5- to 6-h intervals over a single day. Prevention and control measures are also discussed.

Significance of bile-duct changes in schistosomiasis

Lesions involving the intra-hepatic biliary ducts in schistosomiasis have been reported in the literature, both in mice and man, but there are no data concerning their quantitative, evolutionary or post curative chemotherapeutic aspects on record. In order to obtain such data an investigation on this subject was attempted. Mice infected with 50 Schistosoma mansoni cercariae were submitted to a liver biopsy at the 9th week post-infection, and treated with 400 mg/bw praziquantel immediately afterwards. Infected and non-infected controls were submitted to the same procedures. By 19 weeks from cercarial exposure all surviving animals were sacrificed. The biliary ducts were counted on histological sections and the results were expressed as biliary ducts/portal spaces. This quantitative evaluation was compared with that from normal controls and revealed hyperplasia as the main biliary duct change (p<0.007) in schistosomiasis. Hyperplastic changes underwent only mild partial and not statistically significant regression after specific chemotherapy (p>0.05). Infected and untreated animals presented ductal changes that did not differ from those of the treated group. Measurements of serum bilirubin (total and direct), and gamma-glutamyl-transpeptidase (gamma-GT) did not reveal significant differences when animals from the several groups were compared. Thus, bile ducts exhibit a proliferative response in relation to neighboring S. mansoni injury to portal areas, but although these lesions are histopathologically impressive, they lack a functional or prognostic significance.

MUC1 and MUC5AC mucin expression in liver fluke-associated intrahepatic cholangiocarcinoma

AIM: To investigate the expressions of MUC1 and MUC5AC in intrahepatic cholangiocarcinoma (ICC). Association of expressions of mucins MUC1 and MUC5AC with clinical findings, metastasis, and survival of the liver fluke-associated ICC patients was determined.

METHODS: The expressions of MUC1 and MUC5AC mucins were examined by immunohistochemical staining in 87 cases of histologically-proven ICC. The expressions of mucins in relationship between clinicopathological significance and prognosis of the patients were evaluated.

RESULTS: Fifty-two patients (60%) exhibited both MUC1 and MUC5AC expressions, whereas 31% expressed either MUC1 or MUC5AC, and 9% expressed neither. High MUC1 immunoreactivity displayed a significant correlation with tumor progression as reflected by vascular invasion (P<0.001), whereas high expression of MUC5AC significantly correlated with neural invasion (P = 0.022) and advanced ICC stage (P = 0.008). Patients with high expression of MUC1 had a significantly shorter survival (P = 0.0002). According to multivariate analyses, MUC1 reactivity (P = 0.026), histological grading and stage of tumor represented the least probability of survival.

CONCLUSION: MUC1 is overexpressed in liver fluke-associated cholangiocarcinoma and relates to vascular invasion and poor prognosis, whereas MUC5AC mucin is neoexpressed and relates to neural invasion and advanced ICC stage. High MUC1 expression in tumor may be useful for predicting the poor outcome of ICC patients.

Establishment and characterization of an opisthorchiasis-associated cholangiocarcinoma cell line (KKU-100)

AIM: To establish and characterize a new cholangiocarcinoma cell line from a patient living in the Opisthorchis viverrini (O. viverrini) endemic area of Northeast Thailand.

METHODS: Fresh liver biopsy and bile specimens were obtained from a 65-year-old Thai woman with cholangiocarcinoma of the porta hepatis. After digestion, the cells were cultured in Ham’s F12 media. The established cell line was then characterized for growth kinetics, cell morphology, imm-unocytochemistry and cytogenetics. Tumorigenicity of the cell line was determined by heterotransplanting in nude mice.

RESULTS: The primary tumor was a poorly differentiated tubular adenocarcinoma. Examination of the bile revealed malignant cells with O. viverrini eggs. The cholangioc-arcinoma cell line KKU-100 was established 4 mo after the primary culture-population doubling time was 72 h. KKU-100 possesses compact and polygonal-shaped epithelial cells. Immunocytochemically, this cell line exhibited cytokeratin, EMA, CEA, and CA125, but not α-fetoprotein (AFP), CA19-9, desmin, c-met, or p53. Such protein expressions parallel those of the primary tumor. Cytogenetic analysis identified aneuploidy karyotypes with a modal chromosome number of 78 and marked chromosomal structural changes. Inoculation of KKU-100 cells into nude mice produced a transplantable, poorly differentiated aden-ocarcinoma, similar to the original tumor.

CONCLUSION: KKU-100 is the first egg-proven, Opisthorchis-associated cholangiocarcinoma cell line, which should prove useful for further investigations of the tumor biology of this cancer.

Prevalence of Opisthorchis viverrini infection and incidence of cholangiocarcinoma in Khon Kaen, Northeast Thailand

Liver cancer is the most common cancer in Khon Kaen, Northeast Thailand, because of the high incidence of cholangiocarcinoma (CHCA). Opisthorchis viverrini (OV), a liver fluke, is endemic in the area, and has been evaluated as a cause of CHCA by International Agency for Research on Cancer. Residents of 20 districts in the province were invited to attend a mobile screening programme between 1990 and 2001. Of 24 723 participants, 18 393 aged 35-69 years were tested for OV infection, by examining stools for the presence of eggs. Prevalence of infection in each district was estimated from the sample of the population who had been tested. The incidence of liver cancer in 1990-2001 was obtained for each district from the cancer registry. The average crude prevalence of OV infection in the sample subjects was 24.5%, ranging from 2.1% to 70.8% in different districts. Truncated age-standardized incidence of CHCA at ages >35 years varied threefold between districts, from 93.8 to 317.6 per 100,000 person-years. After adjustment for age group, sex and period of sampling, there was a positive association between prevalence of OV infection and incidence of CHCA at the population level. Associations between CHCA and active OV infection in individuals have become hard to demonstrate, because of effective anti-OV treatment. The relationship may, however, be clear in comparisons between populations, which, for infectious diseases, take into account the contextual effects of group exposure in determining individual outcome. The cancer registry is an appropriate tool for disease monitoring in small areas.