• Parasites, Hosts and Diseases
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• v.38 no.3
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• pp.167-171
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• 2000

We report a chronic cerebral paragonimiasis from a 41-year-old Korean man who complains a headache and weakness of left motor neuron components. Magnetic resonance images of the brain revealed conglomerates of multiple ring-like enhancements in tempore-occipital and frontal lobes of the right hemisphere. An intradermal test for paragonimiasis westermani was positive. The patient was born near an endemic area of paragonimiasis and used to eat boiled or grilled freshwater crayfish in his childhood. Nodules in the brain were resected through craniotomies. The eggs of P. westemani were identified pathologically and parasitologically in the calcified necrotic lesions. Examinations on sputum and fecal specimens for the eggs of P. westemani were shown to be negative and a chest radiograph was normal. It is presumed that the brain lesions were formed by P. westemani approximately 30 years ago.

• 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.35 no.2
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• pp.139-142
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• 1997

Cleaving host immunoglobulins is a well known mechanism of evading host immune reactions exploited by helminth parasites, Secreted cysteine proteases of helminth are a part of enzymes cleaving host IgG. Porogonimw westemani produces at least six different species of the cysteine protease in its developmental stages. This study was undertaken to evaluate comparatively the activities against human IgG by the different enzymes. When the metacercariae, which secrete 27 and 28 kDa cysteine proteases, were incubated in human IgG solution, IgG was degraded at its hinge region. Further incubation resulted complete hydrolysis. From 4-week and 7-week old juveniles and 16-week old adults of p. westemani, five different enzymes at 15, 17. 27 28 and 53 kDa have been purified, if the enzyme with the same molecular mass is regarded to be identical. In cleaving human IgG, each cysteine protease exhibited decreasing activities with age.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.231-242
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• 1994

Pnragonimus westermnni, the lung fluke, is known to migrate to the pulmonary tissue of mammalian hosts and causes pathological changes in the lungs. An acidic thiol-dependent proteinase with a molecular weight of approximately 20,000 daltons was purified to homogeneity using ion-exchange chromatography and gel filtration chromatography. On SDS-PAGE, the molecular weight of the enzyme was 17,500 daltons. Isoelectric point was 6.45. The enzyme was similar to the acidic cysteine proteinase of vertebrates in the properties of pH optimum, substrate specificity and inhibitor sensitivity. Enzymatic activity was stable at pH 5.5 for at least two days when stored at 4℃. The cysteine proteinase was capable of degrading collagen and hemoglobin. Sera of patients with paragonimiasis and mice infected with R westermani reacted in immunoblots with the partially purified proteinase. This result suggested that the cysteine proteinase of P. westermnni may play a role in migration in tissues, and in acquisition of nutrients by parasites from the host. It is also potentially an antigen for the serodiagnosis of paragonimiasis.

• Parasites, Hosts and Diseases
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• v.35 no.1
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• pp.47-54
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• 1997

It is generally accepted that parasite-specific IgE plays a crucial role in host defense against helminthic parasites. However, the role of high levels of nonspecific IgE in helminthic infections is still controversial. To investigate the role of nonspecific IgE in primary infections with P. westemani the effect of anti-lgE mAb treatment on serum IgE, $Fc{\varepsilon}RII/CD23$ expression and worm burden in Parcgonimus-infected mice were examined. In mice treated with anti-lgE antibody, the total IgE levels were not detectable ($1{\;}{\mu\textrm{g}/ml}$) throughout the experiment compared with untreated infected mice. The mean percentages of $Fc{\varepsilon}RII/CD23$ positive splenic B cells in anti-lgE treated mice (ridge: 20.3 - 30.5) were also decreased throughout the experiment compared with untreated infected mice (range: 35.7-44.4). Reduction of the total IgE and expression of $Fc{\varepsilon}RII/CD23$ on splenic B cells resulted in decreased worm burden six weeks post infection. These results suggest that high levels of nonspecific IgE in mice with primary infections of P. westemnni play a harmful, rather than beneficial, role for the host, perhaps by interfering with CD23-dependent cellular pathways.