• Parasites, Hosts and Diseases
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• v.37 no.4
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• pp.285-287
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• 1999

Changes in the expression level of splenocyte $IFN-{\gamma}$mRNA of Sprague-Dawley (SD) rats infected with Paragonimus westermani were analyzed by competitive reverse transcription-polymerase chain reaction (RT-PCR) followed by southern blot. The template RNA was extracted from the splenocytes of rats infected with 20 metacercariae of P. westermani. The products of competitive RT-PCR were subjected to southern blot and enhanced chemiluminescence (ECL), and analyzed with a densitometer. In comparison with that of uninfected control rat splenocytes (value of 1), the levels of mRNA expression of $IFN-{\gamma}$had changed to 0.747 at 1 week post infection (PI), 0.00175 at 2 week PI, 0.0217 at 3 week PI, 0.194 at 4 week PI and then to 0.537 at 5 week PI. The level at 7 week PI had returned to 1.25, comparable with that of uninfected rats. These results show that, when infected with p. westermani, the levels of $IFN-{\gamma}$ mRNA of SD rat splenocytes were remarkably reduced by more than 500 times at 2 week PI and restored to normal level at 7 week PI.

• Parasites, Hosts and Diseases
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• v.47 no.4
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• pp.425-426
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• 2009

The present study investigated the infection status of Paragonimus westermani metacercariae in freshwater crabs (n = 363) and crayfish (n = 31) from October 2007 to October 2008 using the crush method. All of the freshwater crabs, Eriocheir japonicus, were negative for P. westermani metacercariae while 10 (32.3%) of the 31 examined crayfish were positive. The 10 positive crayfish were caught in Haenam, Jeollanam-do, and there were 8-59 (mean 28.4) metacrcariae per infected crayfish. These results suggest that P. westermani metacerariae are still transmitted by crayfish enzootically in southern Korea, and that freshwater crabs may transmit metacercariae only on rare occasions.

• Parasites, Hosts and Diseases
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• v.44 no.3
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• pp.187-196
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• 2006

The mammalian trematode Paragonimus westermani is a typical digenetic parasite, which can cause paragonimiasis in humans. Host tissues and blood cells are important sources of nutrients for development, growth and reproduction of P. westermani. In this study, a cDNA clone encoding a 47 kDa hemoglobinase of P. westermani was characterized by sequencing analysis, and its localization was investigated immunohistochemically. The phylogenetic tree prepared based on the hemoglobinase gene showed high homology with hemoglobinases of Fasciola hepatica and Schistosoma spp. Moreover, recombinant P. westermani hemoglobinase degradaded human hemoglobin at acidic pH (from 3.0 to 5.5) and its activity was almost completely inhibited by E-64, a cysteine proteinase inhibitor. Immunohistochemical studies showed that P. westermani hemoglobinase was localized in the epithelium of the adult worm intestine implying that the protein has a specific function. These observations suggest that hemoglobinase may act as a digestive enzyme for acquisition of nutrients from host hemoglobin. Further investigations may provide insights into hemoglobin catabolism in P. westermani.

• Journal of Chest Surgery
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• v.12 no.4
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• pp.312-317
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• 1979

1] During the period of Jan. 1959, to Aug. 1979, 47 patients of paragonimiasis have been treated in the department of Chest Surgery. 2] The total number of patients who has been admitted and treated in the department of Chest Medicine are 262 and annual distribution of number of patients has been decreased. However, since 1964, the number of patients has been stationary. On the other hand, the total number of patients who has been admitted and treated surgically in the department of Chest Surgery are 47 and the annual distribution of number of patients has not been decreased. 3] The peak age incidence lies in fourth decade [34%], and over halves of patients is in third to fifth decade. Male to female is 8.4 to 1. 4] The symptoms, which are mainly cough, chest pain, dyspnea and blood tinged sputum, developed mostly in two to five years after infestation by Paragonmius westermani. 5] Sputum tests for eggs of Paragonimus westermani were positive in 16 out of 43 patients [37%]. The 93% of patients were positive in skin test for Paragonimus westermani. The patients with negative skin test were 7%, but sputum or stool examination for Paragonimus westermani`s eggs were positive in these negative group of skin test. 6] Chest roentgenogram revealed pleural effusion [41 cases], hydropneumothorax [1 case], atelectasis [1 case] and mediastinal mass [1 case]. 7] All patients were preoperatively treated with Bithionol. The mode of surgery were decortication only [31 cases], pleuropneumonectomy [3 cases], decortication & lobectomy [2 cases], decortication & closure of bronchial fistula [1 case], thoracentesis [1 case] and postural drainage [1 case]. 8] Paragonimiasis is primarily medical disease and well treated by the administration of Bithionol. But the delayed diagnosis and missed diagnosis, especially as pulmonary tuberculosis, make the disease aggravated and chronic. Subsequently, surgical treatment is infrequently required. Chronic empyema due to Paragonimus westermani is much benign than tuberculous empyema thoracis.

• Parasites, Hosts and Diseases
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• v.38 no.1
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• pp.17-23
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• 2000

Eosinophils are important effector cells in host defense against parasites. Excretory-secretory product (ESP) produced by helminthic worms plays important roles in the uptake of nutrients, migration in the host tissue, and in immune modulation. However little is known about the ability of the ESP to directly trigger eosinophil apoptosis. This study investigated whether the ESP of newly excysted metacercariae of Paragonimus westermani could induce apoptosis in human eosinophils. Apoptosis was assayed by staining the cells with FITC-annexin V, and the cells were analyzed by flow cytometry. It was found that the ESP of newly excysted metacercariae of P. westemani induced a direct time- and concentration-dependent increase in the rate of constitutive apoptosis in mature human eosinophils. Eosinophil apoptosis was first apparent 3 hr after treatment with the ESP and continued to increase after 6 hr of incubation with respect to the cells cultured in the absence of the ESP. While only 2.8% of the eosinophils incubated in the medium for 3 hr were apoptotic, 7.6%, 10.9% and 22.6% of the eosinophils treated with 10. 30 and $100{\;}\mu\textrm{g}/ml$ ESP were apoptotic, respectively. This result suggests that the ESP of newly excysted metacercariae of P. westermani directly induce eosinophil apoptosis, which may be important for the survival of the parasites and the reduction of eosinophilic inflammation in vivo.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.397-402
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• 1991

Paragonimus westermani is a common fluke in Korea. The present study aimed to determine serum total IgE and specific IgG levels in experimental paragonimiasis of rats. Each Wistar rat was inoculated orally with 20~25 metacercariae of P. westermani from Cambaroides similis. Before and after infection(1,2,3,4,6,8 weeks) of P. westermani, the blood was collected from the retro- orbital venous plexus of rats and kept serum at $-70^{\circ}C$. Serum total IgE and specific IgG levels were determined by the capture and conventional enzyme-linked immunosorbent assay, respectively. The results were as follows; 1. Serum IgE values were increased to 0. 18${\pm}$0.042 at 2 weeks, $0.28{\pm}0.151$ at 4 weeks and 0.43${\pm}0.055$ at 8 weeks after infection. The absorbances of non-infected rats ranged $0.07{\pm}0.021~0.12{\pm}0.025$. 2. Specific IgG values were slightly increased at 3 weeks ($0.20{\pm}$0.032) and gradually increased up to 8 weeks($0.31{\pm}0.067$) after infection. The absorbances of non-infected rats ranged $0.11{\pm}0.035~0.18{\pm}0.019$. The present results suggested that p. westermani could elevate serum IgE and specific IgG antibodies in Wistar rats which were not a good definitive host.

• Parasites, Hosts and Diseases
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• v.24 no.2
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• pp.194-200
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• 1986

A study on the population density of crayfish intermediate hosts and infestation status of crayfish with encysted larvae of Paragonimus westermani in Ulchin county, Kyungpook Province, Korea was conducted from May to October in 1986. The population density of the crayfish ranged from 1 to 13, with an average of 4 per man-hour. Among the six habitats, Ducheon had a somewhat higher density than that of the others. Of eight hundred and seventeen crayfish examined, 127 or 15.5 per cent harboured the metacercarial larvae of Paragonimus westermani. The majority of the larvae were found in three parts of the body: most frequently in the cephalothorax, next in the gills, and then in the liver. The average number of metacercarial larvae per infected crayfish ranged from 1.0 to 1.9, with an average of 1.7. Summarizing the results, this study indicates that the population density of crayfish intermediate host and infestation rates for the crayfish with encysted larvae of Paragonimus westermani in Ulchin county of Kyungpook Province is relatively high.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.355-358
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• 1992

In early maturation stages of Paragonimus westermani (metacercariae, 4-, 8-, 12-week old worms), activities of antioxidant enzymes, such as superoxide dismutase, catalase, peroxidase and glutathione peroxidase, were examined. Specific activity of catalase was the highest in metacercariae and decreasing with age. That of superoxide dismutase was higher in metacercariae and 4-week worms. Specific activity of peroxidase was at its peak in 4-week worms while that of glutathione peroxidase was in 8-week worms. Specific activities of all these antioxidant enzymes were decreased to their lowest in 12-week old adults.

• Parasites, Hosts and Diseases
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• v.38 no.2
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• pp.103-106
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• 2000

It is well known that the cysteine proteases in excretory-secretory product (ESP) of Paragonimus westermani newly excysted metacercariae (PwNEM) are capable of degrading IgG in vitro. Recent evidence suggests that the IgG-coated surface, such as found on parasites, is one of the most effective physiologic stimuli for granulocyte activation. Therefore, this study was designed to investigate the effect of excretory-secretory product (ESP) of PwNEM on superoxide production of granulocytes stimulated with IgG The 96-well plates were coated with human IgG (0, 10, 30, $100{\;}\mu\textrm{g}/ml$) in the absence or presence of ESP. When granulocytes were incubated in the wells coated with human IgG in the presence of ESP, the level of superoxide production of granulocytes was reduced to about 90% when compared to the cells incubated in the wells coated with IgG alone. This inhibitory effect of the ESP on IgG-induced superoxide production of granulocytes was concentration-dependent. These results suggest that ESP secreted by PwNEM may be important in the control of effector functions of granulocytes stimulated with IgG in human paragonimiasis.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.64-68
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• 1985

In this study, hybridoma techniques were applied to produce monoclonal antobodies to Paragonimus westermani, commonly known as lung distoma. Balb/c mice were immunized intraperitoneally every week with increasing doses of purfied protein of Paragonimus westermani adult worms begining with 0.3/mg/mouse/7 days and ending with 0.5mg at 28th day. Spleen cells from these immunized mice were hybridized with myeloma cells (NS-1) and the hybridized cells were selected in HAT media. The antibody secreting cells among the hybrid cells were initially selected by ELISA. Those initially selected cells were further screened by the criteria of antibody producing activity, and seneral cell lines among them were further tested with immunodiffusion method. One hybridoma clone produced IgM and another clone produced IgG1. The supernatant of the hybridoma clone producing IgM had titer 1:64 and the hybridoma clone producing IgG1 had titer 1:256 measured by immunofluorescence technique.