• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.257-264
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• 1983

In order to obtain more specific antigenic preparation for the diagnosis of human paragonlmiasis, crude saline extract of whole worm (=PwWWE), secretory.excretory components (PwSEC) and secretion-excretion-free somatic extract (PwSM) of 12 week-old ParagoninBus westermani were filtrated through Sephadex G-200 gel column. The adult Paragonimus worms were obtained from expevimentally infected doge. A total of 11 antigenic solutions was Iyophilised or diluted to adjust protein content of 1mg/ml. To evaluate the antigenicity of crude antigens and fractions, micro-ELISA was done with the sera from P westermani in(ected cases, C. sinensis infected cases and non-infected control cases to detect Paragonimus specific IgG antibody. The results were as follows: 1. When the PwWWE was filtrated through Sephadex G-200 gel, it was separated into three fractions; PwWWE Fr. 1, PwWWE Fr. 2 and PwWWE Fr. 3. The percentage of protein content was 28.0%, 21.6% and 50.4% respectively. The PwSM was also. separated into three fractions; PwSM Fr. 1, PwSM Fr. 2, PwSM Fr. 3. and their percentage of protein content was 41.3%, 38.6% and 20.1%. However, the PwSEC showed different fractionation pattern; i.e. fraction 1 (=PwSEC Fr.1) and 3 (PwSEC Fr. 3) without fraction 2. The percentage of protein content was 14.0% in PwSEC Fr. 1 and 86.0% in PwSEC Fr. 3. 2. When the antigenicity of each Paragonimus crude antigen and fractionated antigen was evaluated for specific IgG aritibody by micro-ELISA in 10 human paragonimiasis sera, PwSEC Fr, 1 was the most potent antigen showing the mean absorbance 1.98. The PwWWE Fr. 1, PwSEC, PwWWE were next to that: their mean absorbance were 1.72, 1.38 and 0.83 respectively. The antigenicity of fractions 2 and 3 was much weaker in binding specific IgG antibody. 3. When the antigens were reacted in micro-ELISA with 10 human clonorchiasis sera, most antigens showed weak reactivity. Each fraction 1 of crude antigens reacted higher than other fractions or crude antigens; the mean absorbance was 0.17 in fraction 1, but in others the absorbances were about 0.06. 4. With non-infected control sera, the result of micro-RLISA revealed almost same pattern with those of the clonorchiasis sera. From the above results, it became apparent that PwWWE Fr. 1, especially PwSEC Fr. 1 was the most potent antigen reacted with Paragonisfaus specific IgG antibody.

• Parasites, Hosts and Diseases
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• v.58 no.3
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• pp.237-247
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• 2020

Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H₂O₂-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.

• Parasites, Hosts and Diseases
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• v.55 no.3
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• pp.295-304
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• 2017

Opisthorchis viverrini infection induces chronic inflammation, and a minor proportion of infected individuals develop advanced periductal fibrosis (APF) and cholangiocarcinoma (CCA). Inflammatory cytokines and/or their gene polymorphisms may link to these biliary pathologies. We therefore investigated associations among cytokine gene polymorphisms and cytokine production in 510 Thai cases infected with O. viverrini who presented with APF+ or APF-, as established by abdominal ultrasonography as well as in patients diagnosed with CCA. Levels of pro-inflammatory and anti-inflammatory cytokines were determined in culture supernatants after stimulation of peripheral blood mononuclear cells (PBMCs) with O. viverrini excretory-secretory (ES) products. Pro-inflammatory cytokines, IL-$1{\beta}$, IL-6, IFN-${\gamma}$, LT-${\alpha}$, and TNF-${\alpha}$ were significantly increased in CCA patients compared with non-CCA (APF- and APF+) cases. Polymorphisms in genes encoding IL-$1{\beta}$-511C/T, IL-6-174G/C, IFN-${\gamma}$+874T/A, LT-${\alpha}$+252A/G, and TNF-${\alpha}$-308G/A were then investigated by using PCR-RFLP or allele specific-PCR (AS-PCR) analyses. In the CCA cases, LT-${\alpha}$+252A/G and TNF-${\alpha}$-308G/A heterozygous and homozygous variants showed significantly higher levels of these cytokines than the wild type. By contrast, levels of cytokines in wild type of IFN-${\gamma}$+874T/A were significantly higher than the variants in CCA cases. IFN-${\gamma}$+874T/A polymorphisms were associated with advanced periductal fibrosis, whereas IL-6-174G/C polymorphisms were associated with CCA. To our knowledge, these findings provide the first demonstration that O. viverrini infected individuals carrying several specific cytokine gene polymorphisms are susceptible to develop fibrosis and CCA.

• Parasites, Hosts and Diseases
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• v.35 no.4
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• pp.259-264
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• 1997

This study was carried out to determine whether dermal mast cell responses to Parasoninn westemoni in an abnormal host, the mouse, were dependent on the site of metacercarial inoculation. In mice during subcutaneous infection, the number of der- mal mast cells were increased significantly (p<0.05) at the first week ($38.3/\textrm{mm}^2$) and then persisted at a high level until the sixth week ($45.2/\textrm{mm}^2$) of infection compared with PBS- injected (control) mice (range: $19.4-25.1/\textrm{mm}^2$). In mice during oral infection, the number of dermal mast cells were increased significantly (p<0.05) at two weeks ($33.5/\textrm{mm}^2$) after infection and remained at these levels thereafter compared loth non-infected (control) mice (range: $17.4-22.3/\textrm{mm}^2$). In mice both during subcutaneous and oral infection, the recruited dermal mast cells showed extensive degranulation at the second week (68.4%) and 60.7%, respectivelyl, reached a peak at the third week (81.4%, and 92.1%, respectively) and then declined slightly thereafter. By contrast, in both control mice, about 10% of dermal mast cells were degranulated. In conclusion, this study suggests that dermal mast cell responses to p. westemcni in mice are dependent on cutaneous sensitization by larval excretory-secretory antigens, irrespective of infection route.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.211-218
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• 1995

To clarify the correlation of the proteinase activity with pathogenicity of Clonorrhis sinensis, the proteinase activity either in excretory-secretory products (ESP) or in crude extracts of adult C. sinensis was examined. Substrate gel electrophoresis of the ESP and crude extracts revealed four distinct enzyme bands, which were differently inhibited by the specific proteinase inhibitors. The proteinase of the ESP with molecular mass of 24 kDa, was purified 23-fold with 14.5% yield by spectra gel ACA 44 gel filtration. It exhibited optimal pH at 7.5 in sodium phosphate (0.1 M). Its activity was inhibited specifically by N-ethylmaleimide (NEMI and antipain whereas potentiated 1.9 folds in the presence of 5 mM dithiothreitol (DTT). Cytotoxicity of the proteinase increased in a dose- dependent manner up to 120 ㎍/ml while reduced by NEM and antipain, indicating that cysteine proteinase was responsible for the cytotoxicity. This result shows that the 24 kDa cysteine proteinase is deeply correlated with the pathogenicity of C. sinensis infection.

• Applied Microscopy
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• v.40 no.2
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• pp.89-99
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• 2010

Fibroblasts are the most common cells in connective tissue and are responsible for the synthesis of extracellular matrix components. The fibrosis associated with chronic inflammation and injury may contribute to cholangiocarcinoma pathogenesis, particularly through an increase in extracellular matrix components, which participate in the regulation of bile duct differentiation during development. Mitochondria produce ATP through oxidative metabolism to provide energy to the cell under physiological conditions. Also, mitochondrial dysfunction and oxidative stress have been implicated in cellular senescence and aging. Alternations in mitochondrial structure and function are early events of programmed cell death or apoptosis and mitochondria appear to be a central regulator of apoptosis in most somatic cell. Clonorchis sinensis, one of the most important parasite of the human bile duct in East Asia, arouses epithelial hyperplasia and ductal fibrosis. Isolated fibroblast from the bile ducts of rats infected by C. sinensis showed increase of cytoplasmic process. In addition, decrease of cellular proliferation was observed in fibroblasts which was isolated from normal rat bile duct and then cultured in media containing C. sinensis excretory-secretory product. However, the effects of C. sinensis infection on the mitochondrial enzyme distribution is not clearly reported yet. Therefore, we investigated the structural change of C. sinensis infected bile duct and mitochondrial enzyme distribution of the cultured fibroblast isolated from the C. sinensis infected rat bile duct. As a result, C. sinensis infected SD rat bile ducts showed the features of chronic clonorchiasis, such as ductal connective and epithelial tissue dilatation, or ductal fibrosis. In addition, fibroblast in ductal connective tissue was damaged by physical effect of fibrotic tissue and chemical stimulation. Immunohistochemically detected mitochondrial electron transferase (ATPase, COXII, Porin) was decreased in C. sinensis infected rat bile duct and cultured fibroblast from infected rat bile duct. It can be hypothesized that the reason why number of electron transferase decrease in fibroblast isolated from the rat bile duct infected with C. sinensis is because dysfunction of electron transport system is occurred mitochondrial dysfunction, increase of ROS (reactive oxygen species) and apoptosis after chemical damage on the cell caused by C. sinensis infection. Overall, C. sinensis infection induces fibrotic change of ductal connective tissue, mutation of cellular metabolism in fibroblast and mitochondrial dysfunction. Consequently, ductal fibrosis inhibits fibroblast proliferation and decreases mitochondrial electron transferase on fibroblast cytoplasm. It was assumed that the structure of bile duct could not normalized and ductal fibrosis was maintained for a long period of time according to fibroblast metamorphosis and death induced by mitochondrial dysfunction.

• Tuberculosis and Respiratory Diseases
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• v.62 no.1
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• pp.19-26
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• 2007

Background: Toxocariasis is a common cause of eosinophilia and eosinophilic lung disease in Korea. We analyzed the characteristics of eosinophilic lung disease in toxocariasis. Method: One hundred and forty one patients with eosinophilia caused by a toxocara larval infection were evaluated from September 1, 2001 through March 30, 2006. The plain chest x-ray, chest CT(computed tomography), and bronchoalveolar larvage(BAL) were examined. A diagnosis of toxocariasis was made by ELISA using that secretory-excretory antigen from the T. canis larvae. Results: Toxocarial eosinophilic lung diseases was diagnosed in 32 out of 141 patients. Ground glass attenuation was the main feature on the CT scans in 23 out of 141 patients (71.9%). Thirteen patients (40.6%) had a random in zonal distribution on CT. Pleural effusion was observed in 9 patients (28.1%). Twenty eight patients (87.5%) complained of respiratory symptoms. Eleven patients (34.4%) had gastrointestinal symptoms and 12 patients (37.5%) had liver infiltration. Conclusions: The most common findings of the chest CT in patients with toxocariasis was a randomly distributed ground grass attenuation. A toxocara infection should be considered in a differential diagnosis of patients who exhibit pulmonary infiltration with eosinophilia in Korea.