Imaging findings of hepatic paragonimiasis : a case report.
(1/21)
Hepatic paragonimiasis is a rare form of ectopic infestation caused by Paragonimus. We experienced a case of hepatic paragonimiasis that showed characteristic imaging findings. CT and MR images showed a cluster of small cysts with rim enhancement in the subcapsular area of the liver. This finding seems to be characteristic for hepatic paragonimiasis, considering imaging findings in paragonimiasis involving other organs. (+info)
Degranulation of human eosinophils induced by Paragonimus westermani-secreted protease.
(2/21)
Eosinophil degranulation is considered to be a key effector function for the killing of helminthic worms and tissue inflammation at worm-infected lesion sites. However, relatively little data are available with regard to eosinophil response after stimulation with worm-secreted products which contain a large quantity of cysteine proteases. In this study, we attempted to determine whether the degranulation of human eosinophils could be induced by the direct stimulation of the excretory-secretory products (ESP) of Paragonimus westermani, which causes pulmonary paragonimiasis in human beings. Incubation of eosinophils for 3 hr with Paragonimus-secreted products resulted in marked degranulation, as evidenced by the release of eosinophil-derived neurotoxin (EDN) in the culture supernatants. Moreover, superoxide anion was produced by eosinophils after stimulation of the ESP. The ESP-induced EDN release was found to be significantly inhibited when the ESP was pretreated with protease inhibitor cocktail or the cysteine protease inhibitor, E-64. These findings suggest that human eosinophils become degranulated in response to P. westermani-secreted proteases, which may contribute to in vivo tissue inflammation around the worms. (+info)
Pleuropulmonary paragonimiasis mimicking pulmonary tuberculosis--a report of three cases.
(3/21)
Paragonimiasis is an important cause of pulmonary disease worldwide. Infection in humans mainly occurs by ingestion of raw or undercooked freshwater crabs or crayfish. The disease is well known in endemic regions of Asian countries, where culturally based methods of food preparation foster human transmission. Three patients with clinical and radiological features compatible with pulmonary tuberculosis had been treated for tuberculosis without remedy despite an inability to demonstrate acid fast bacilli in sputum smears. All patients had history of ingestion of raw crabs and crayfish. The confirmed diagnosis of pleuropulmonary paragonimiasis was made based on the demonstration of Paragonimus eggs in the sputum, and high absolute eosinophilia in their peripheral blood and pleural fluid. All the patients had been treated with praziquantel successfully. (+info)
Paragonimus westermani and some rare intestinal trematodes recovered from raccoon dogs (Nyctereutes procyonoides viverrinus) introduced recently on Yakushima Island, Japan.
(4/21)
Helminth parasites were collected from 9 raccoon dogs (Nyctereutes procyonoides viverrinus) and 2 Japanese weasels (Mustela itatsi sho) on Yakushima Island, Japan. The former carnivore was introduced to this World Natural Heritage Area presumably within the last two decades, expanding its population thence, although detailed process(es) of the introduction is unknown. The collected trematodes from raccoon dogs included the triploid form of Paragonimus westermani, Brachylaima tokudai, Maritrema eroliae, and Pseudocryptotropa sp. Simultaneously, Paragonimus ohirai was found in one weasel killed by a traffic accident. Although the triploid form of P. westermani and P. ohirai are known to be distributed in some river-mouth areas of Yakushima Island based on previous surveys on crab hosts, natural infection was detected for the first time in wild final hosts. Particularly, the raccoon dog infected with P. westermani was caught in a mountainous area, distant from human residence or river-mouth areas. Although it is possible that the infected raccoon dog moved from a river-mouth area endemic with P. westermani after infection, the alternative scenario remains to be pursued; the endemic area of this zoonosis is expanding along with the recent expansion of raccoon dogs or feral cats (Felis catus), that became prevalent recently on this island including the mountainous areas. Maritrema eroliae taking a variety of shorebirds as its natural final hosts, and a minute trematode, Pseudocryptotropa sp., taking unknown natural final host(s) were recorded for the first time in raccoon dogs. (+info)
Molecular and biochemical characterization of hemoglobinase, a cysteine proteinase, in Paragonimus westermani.
(5/21)
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. (+info)
Serial CT findings of Paragonimus infested dogs and the Micro-CT findings of the worm cysts.
(6/21)
OBJECTIVE: To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. MATERIALS AND METHODS: This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. RESULTS: The initial findings were pleural effusion and/or subpleural ground-glass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. CONCLUSION: The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus. (+info)
Pulmonary paragonimiasis with coincidental malignant mesothelioma.
(7/21)
A 72-year-old man patient was referred to our institution for evaluation and treatment of right pleural effusion. Eosinophilic pleural effusion and peripheral eosinophilia were identified during the course of hospitalization. Pulmonary paragonimiasis was confirmed by the presence of paragonimus-specific IgG antibodies for Paragonimus (P.) westermani and P. miyazakii in his serum. Although Praziquantel, a highly effective agent for the treatment of lung flukes was repeatedly administered, the pleural effusion did not subside and the patient's condition gradually deteriorated until his death due to circulatory insufficiency. Postmortem examination revealed malignant mesothelioma of the sarcomatous type encasing the right lung and heart. Cardiac involvement accompanied with old and recent-onset myocardial ischemic changes resulted in death of this patient. Here, we report a very rare case of malignant mesothelioma with a concomitant infection of parasitic lung fluke. (+info)
A 27 kDa cysteine protease secreted by newly excysted Paragonimus westermani metacercariae induces superoxide anion production and degranulation of human eosinophils.
(8/21)