Despite the existence of effective anthelmintics, parasitic infections remain a major public health problem in Southeast Asia, including Thailand. In rural communities, continuing infection is often reinforced by dietary habits that have a strong cultural basis and by poor personal hygiene and sanitation. This study presents a survey of the prevalence of intestinal parasitic infections among the people in rural Thailand. The community-based cross-sectional study was conducted in villages in Khon Kaen Province, northeastern Thailand, from March to August 2013. A total of 253 stool samples from 102 males and 140 females, aged 2-80 years, were prepared using formalin-ethyl acetate concentration methods and examined using light microscopy. Ninety-four individuals (37.2%) were infected with 1 or more parasite species. Presence of parasitic infection was significantly correlated with gender (P=0.001); nearly half of males in this survey (49.0%) were infected. Older people had a higher prevalence than younger members of the population. The most common parasite found was Opisthorchis viverrini (26.9%), followed by Strongyloides stercoralis (9.5%), Taenia spp. (1.6%), echinostomes (0.4%), and hookworms (0.4%). The prevalence of intestinal protozoa was Blastocystis hominis 1.6%, Entamoeba histolytica 0.8%, Entamoeba coli 0.8%, Balantidium coli 0.4%, Iodamoeba bütschlii 0.4%, and Sarcocystis hominis 0.4%. Co-infections of various helminths and protozoa were present in 15.9% of the people. The present results show that the prevalence of parasitic infections in this region is still high. Proactive education about dietary habits, personal hygiene, and sanitation should be provided to the people in this community to reduce the prevalence of intestinal parasite infections. Moreover, development of policies and programs to control parasites is needed.

We investigated the utility of various animal models for the study of opisthorchiasis in humans and its common sequel of cholangiocarcinoma (CCA). Rats, mice, gerbils, and hamsters were infected with Opisthorchis viverrini metacercariae. Worms from the infected animal hosts were recovered from livers and counts made of eggs per gram of feces. Worms were observed in and recovered from hamsters and gerbils but not rats and mice. The recovered worms from the infected gerbils were larger and more physiologically developed than those from the infected hamsters. The results suggest that gerbils are more susceptible to infection by Opisthorchis viverrini and thus more suitable for modeling opisthorchiasis and its connection to CCA.

Cholangiocarcinoma (CCA) is a malignancy of bile duct with the difficulty in early diagnosis, poor prognosis and less alternation in therapy. S100P is a member of S100 family proteins and plays important roles in cancers. We investigated the S100P expression and its correlation with clinicopathology in 78 cases of opisthorchiasis-associated CCA, and the effects of S100P knockdown with shRNA interference on the proliferation, cell cycle, migration, apoptosis and sensitivity to anti-cancer drug. Extremely high expression of S100P mRNA was detected in the CCA tumor tissues. The increased S100P protein expression was immunohistochemically confirmed and localized in the CCA cytoplasm and/or nuclei as well as in the hyperneoplasia and dysplasia bile ducts, but not in normal bile ducts. The intensity of immunostaining was correlated with survival, tumor stage and metastasis, and the high expression could be an independent prognostic factor. High levels of S100P were detected in the serum and bile fluid of CCA patients. The shRNA-mediated knockdown of S100P expression inhibited the proliferation in vitro and in vivo, and migration of CCA cells, arrested cell cycle with the up-regulated expression of cell cycle arrest related factors, p21, p27, GADD45A, and 14-3-3 zeta. S100P knockdown also promoted CCA cell apoptosis by up-regulating expression of apoptosis related factors, DR5, TRADD, caspase 3 and BAX, and increased the sensitivity of CCA cells to the chemotherapeutic agents sunitinib and apigenin. Taken together, this study indicates that S100P might be a promising biomarker for the diagnosis, prognosis and therapy of CCA.Cholangiocarcinoma (CCA) is a malignancy arising from bile ducts. Although it is rare, the incidence and mortality of the cancer have been increasing worldwide over the past decades, while the prognosis is remained dismal and substantially unchanged.1 Because of the lack of the method of early diagnosis, most of patients, when diagnosed, are incurable advanced and metastatic; their 5-year survival rate is extremely low. Chronic inflammation is one of important risks of CCA tumorigenesis, including Opisthorchis viverrini infection. Clear relationship between O. viverrini infection and CCA incidence has been demonstrated.2,3 The epidemiological investigations have indicated the astonished high incidence of CCA in opisthorchiasis endemic areas, especially in northeast of Thailand where both opisthorchiasis prevalence and CCA incidence are the highest in the world. 4,5 Serious O. viverrini infection, the lack of early diagnostic methods and poor prognosis of CCA put the millions of people at the risk of CCA in endemic areas. Although many efforts have been made, the biomarkers for diagnosis, prognosis and therapy of CCA are still quite limited. Therefore, it is urgent to delve into the tumorigenesis mechanism and develop novel biomarkers for the early diagnosis, prognosis, and therapy of the opisthorchiasis-associated CCA.Our previous cDNA microarray analysis showed that some of S100 proteins were up-re...

Our previous report showed that platelet-derived growth factor (PDGF) and related genes were upregulated in a Syrian hamster model and could be detected in all human cholangiocarcinoma (CCA) tissues. We therefore hoped that PDGF could be used as a diagnostic and prognostic marker. We analyzed 78 samples of human CCA and adjacent tissues for PDGF and related gene expression, and localized PDGF protein expression. The mechanism of anti-cancer drugs on PDGF and related genes or proteins in CCA cell lines (OCA17, M156, and KKU100) was studied through MTT cell viability assay, quantitative real-time PCR, and immunoblotting. Mutagenesis of the PDGFRA coding region was analyzed. Moreover, the PDGFRA in sera of CCA patients and healthy controls was investigated. PDGFA was found to be upregulated in CCA tissue (84.6 %). Positive PDGFA immunohistochemical staining was significantly correlated with status (P = 0.000), stage of CCA (P = 0.013), metastasis (P = 0.017), and short survival rate (P = 0.005), and the multivariate analysis confirmed that PDGFA positive immunostaining had a higher likelihood of the risk of death (HR = 2.907, P = 0.016). For DNA point mutation of the PDGFRA sequence, silent mutations were found at tyrosine kinase 2 V824V (exon 18) and A603A (exon 13), and a missense mutation in S478P (exon 10); there was only a missense mutation in S478P (29 %) that has significant correlation with the histopathological grading (P = 0.037) and positive immunoreactive PDGFA (P = 0.021). In vitro cell line study by immunowestern blotting found that sunitinib malate had an inhibitory effect on the PDGFA pathway by decreasing p-PDGFRA, AKT, and p-AKT expression. The serum level of PDGFA in CCA patients was significantly higher than those of healthy control by 1.4-fold (P = 0.014). The present results suggest that PDGFA and PDGFRA may be used for CCA prognosis and/or as diagnostic candidate markers.